USRE36352E - High-efficiency, multilevel, diffractive optical elements - Google Patents

High-efficiency, multilevel, diffractive optical elements Download PDF

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USRE36352E
USRE36352E US08/471,863 US47186395A USRE36352E US RE36352 E USRE36352 E US RE36352E US 47186395 A US47186395 A US 47186395A US RE36352 E USRE36352 E US RE36352E
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masks
levels
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optical element
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Gary J. Swanson
Wilfrid B. Veldkamp
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Massachusetts Institute of Technology
DigitalOptics Corp East
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    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70Microphotolithographic exposure; Apparatus therefor
    • G03F7/70216Mask projection systems
    • G03F7/70308Optical correction elements, filters or phase plates for manipulating imaging light, e.g. intensity, wavelength, polarisation, phase or image shift
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/42Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
    • G02B27/4205Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
    • G02B27/4211Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant correcting chromatic aberrations
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/42Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
    • G02B27/4205Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
    • G02B27/4216Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant correcting geometrical aberrations
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/42Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
    • G02B27/4205Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
    • G02B27/4222Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant in projection exposure systems, e.g. photolithographic systems
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00Simple or compound lenses
    • G02B3/02Simple or compound lenses with non-spherical faces
    • G02B3/08Simple or compound lenses with non-spherical faces with discontinuous faces, e.g. Fresnel lens
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/18Diffraction gratings
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/18Diffraction gratings
    • G02B5/1847Manufacturing methods
    • G02B5/1857Manufacturing methods using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/18Diffraction gratings
    • G02B5/1876Diffractive Fresnel lenses; Zone plates; Kinoforms
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F1/00Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/0005Production of optical devices or components in so far as characterised by the lithographic processes or materials used therefor
    • G03F7/001Phase modulating patterns, e.g. refractive index patterns

Definitions

  • This invention relates to high-efficiency, on-axis, multilevel, diffractive optical elements.
  • the high efficiency of these elements allows planar or spherical elements to be diffractively converted to generalized aspheres, and dispersive materials can be diffractively compensated to behave as achromatic materials over broad wavebands.
  • the technique of this disclosure allows ready implementation of this mixed reflective, refractive and diffractive optics in real systems.
  • phase profiles allow for an additional degree of freedom in designing optical systems.
  • System design is restricted by constraints imposed by factors such as cost, size, and allowable asphericity.
  • Diffractive elements are potentially as versatile and useful as aspheric surfaces and are less expensive, and not as subject to asphericity constraints.
  • Another objective in designing optical systems is to minimize chromatic aberrations.
  • Refractive optical materials are chromatically dispersive. Conventionally, the approach to minimizing chromatic aberrations is to balance the dispersive effects of two different refractive materials.
  • Diffractive surfaces are also wavelength dispersive.
  • on-axis diffractive phase elements can achieve 100% diffraction efficiency. To achieve this efficiency, however, a continuous phase profile is necessary. (See, Miyamoto, K., 1961, JOSA 51, 17 and Lesem, L., Hirsch, P., Jordan, J., 1969, IBM J. Res. Dev. 13, 150.)
  • the technology for producing high-quality, high-efficiency, continuous phase profiles does not exist. It has been suggested to quantize the continuous phase profile into discrete phase levels as an approximation to the continuous phase profile. (Goodman, J., Silvestri, A., 1970, IBM J. Res. Dev. 14, 478.) It is known to make such structures using thin-film deposition techniques and material cutting technology. (See, U.K.
  • L. d'Auria et al. in "Photolithographic Fabrication of Thin Film Lenses", OPTICS COMMUNICATIONS, Volume 5, Number 4, July, 1972 discloses a multilevel structure involving successive maskings and etchings of a silicon dioxide layer. Each mask gives only one additional level in the structure and is therefore inefficient.
  • the invention disclosed herein is a method for accurately and reliably making multilevel diffractive surfaces with diffraction efficiencies that can be as high as 99%.
  • the method for making high-efficiency, multilevel, diffractive, optical elements comprises generating a plurality of binary amplitude masks which include the multilevel phase information.
  • the masks are configured to provide 2 N levels where N is the number of masks.
  • the information in each mask is utilized serially for serial etching of the multilevel structures into the optical element.
  • the masks may be made by electron beam lithography and it is preferred that the etching be accomplished by a dry etching technique such as reactive ion etching or ion bombardment.
  • the etching process includes coating the optical element substrate with a photoresist, exposing the photoresist through the masks, developing the photoresist, and etching the substrate. In order to achieve greater than 95% efficiency, three masks and three etching steps are used to produce eight phase levels.
  • An important use of the structures of the invention is in UV lithography.
  • FIGS. 1a, 1b and 1c are schematic illustrations of Fresnel phase zone plate profiles
  • FIG. 2 is a graph of first order diffraction efficiency in a multilevel zone plate as a function of the number of phase levels and fabrication masks;
  • FIG. 3 is a schematic representation of a binary element fabrication technique disclosed herein;
  • FIG. 4 is a scanning electron microscope photomicrograph of an eight-level Fresnel zone plate made in accordance with the present invention.
  • FIGS. 5a and 5b are diffraction patterns showing spherical aberration in an uncorrected and corrected quartz lens, respectively;
  • FIG. 6 is a graph showing diffractive and refractive dispersion
  • FIGS. 7a, b and c are point spread function plots showing diffractive correction of silicon lenses
  • FIG. 8 is a photograph of the diffractively corrected silicon lens.
  • FIG. 9 is a schematic illustration of a UV lithographic exposure system utilizing the multilevel structures of the invention.
  • FIG. 1a shows an example of a Fresnel zone plate having a continuous phase profile capable of achieving 100% efficiency.
  • the 2 ⁇ phase depth corresponds to a material depth of about one micrometer for visible light. Because the technology to produce the continuous phase profile of FIG. 1a does not exist, an approximation to the continuous phase is desirable.
  • FIGS. 1b and 1c show Fresnel phase zone plate profiles quantized to two and four phase levels, respectively.
  • the two-level phase.[.,.]. profile of FIG. 1b results in a diffraction efficiency of 40.5%
  • the four-level profile of FIG. 1c results in an efficiency of 81%.
  • FIG. 2 shows the diffraction efficiency as a function of the number of discrete phase levels. Eight phase levels achieve 95% efficiency.
  • the method of the invention accurately and reliably produces multilevel, on-axis, diffractive optical surfaces.
  • Optical elements can be made for use at wavelengths ranging from the ultraviolet to the infrared. These multilevel structures are useful not only for monochromatic light, but also for systems operating with fractional bandwidths as large as 40%.
  • the methods disclosed herein take advantage of technology developed for electronic circuit fabrication such as high resolution lithography, mask aligning, and reactive ion etching. The process for defining the phase profile to be constructed will now be discussed.
  • phase Fresnel zone plate Collimated monochromatic light incident on a phase Fresnel zone plate (FIG. 1a) will be diffracted with the light being focused perfectly.
  • the necessary phase profile can be expressed in the simple form ##EQU1## where ⁇ is the wavelength, F the focal length, and ⁇ is evaluated modulo 2 ⁇ .
  • the phase Fresnel zone plate is an interesting yet limited example of a profile. In general, it is desirable to define arbitrary diffractive phase profiles.
  • phase profile is described by making an analogy to the optical recording of holographic optical elements.
  • the wavelength and location in space of two coherent point sources are defined and the resulting interference pattern describes the diffractive phase profile.
  • This process describes more general profiles than a simple zone plate, however, which is still a small subset of the possible profiles.
  • an additional phase term ##EQU2## can be added onto the phase determined from the two point sources. For on-axis phase profiles, the two point sources must lie on the optical axis.
  • Lens design programs have optimization routines that treat the curvatures of surfaces, the thickness of elements, and the element spacings as variables. Likewise, if a diffractive phase profile is in the system, the optimization routine can treat the polynomial coefficients, a nm , as variables. A lens optimization program will determine the optimum coefficients, a nm , of the diffractive phase profile for any particular lens systems.
  • the diffractive phase profile determined by the lens design program and defined by equation (2) contains no information on, how to achieve high diffraction efficiency.
  • Our approach is to take the optimized a nm 's and from them define a set of binary amplitude masks. The algorithm for designing these masks is shown in Table 1.
  • Mask 1 describes the set of equiphase contours that are integer multiple of ⁇ .
  • the area between the first two sequential equiphase boundaries is lithographically exposed.
  • the areas between subsequent sequential equiphase boundaries alternate from not being exposed to being exposed. This process is repeated until the total pattern is drawn, covering the full optical aperture.
  • Table 1 also indicates the phase depth ⁇ to which various lithographic mask patterns are etched.
  • the relationship between phase depth and materials depth d is simply ##EQU3## where n is the refractive index of the optical material.
  • Lithographic pattern generators are capable of drawing binary amplitude masks with feature sizes of 0.1 ⁇ m and positioning the features to an even greater accuracy.
  • Reactive ion etchers can etch a binary profile to depths of a few microns with an accuracy on the order of tens of angstroms.
  • Mask aligners are used routinely to align two patterns with an accuracy of fractions of a micron.
  • Electron beam pattern generators produce masks that have binary transmittance profiles.
  • a thin layer of chromium on an optically flat quartz substrate is patterned by e-beam lithography.
  • the input to the e-beam pattern generator is a file stored on a computer tape and properly formatted for the particular machine.
  • the algorithm described in Table 1 defines the patterns to be drawn.
  • the number of phase levels in the final diffractive element constructed from these masks is 2 N , where N is the number of masks. For example, only four masks will produce 16 phase level resulting in an efficiency of 99%.
  • the binary amplitude masks produced from the pattern generator are then used in a serial fashion to construct the multilevel optical element.
  • the fabrication process using the first mask is shown in FIG. 3.
  • An optical substrate 10 such as SiO 2 on which the diffractive profile is to reside is coated with a layer of chromium 12 and a layer of photoresist 14.
  • An e-beam generated mask 16 is then placed over the substrate 10 and illuminated with a standard uv photoresist exposure system (not shown).
  • the photoresist layer 14 is then developed resulting in a properly patterned layer of photoresist.
  • the photoresist acts as an etch stop for the reactive ion etching.
  • Reactive ion etching is a process in which an RF electric field excites a gas to produce ions. The ions react with the material of the substrate and etch away the surface at a controlled rate.
  • the reactive ion etching process is anisotropic so that the vertical side walls of the discrete phase profile are retained.
  • Typical RIE etch rates are on the order of 100 Angstroms to 200 Angstroms per minute.
  • the required first level etch depth for a quartz substrate to be used at a wavelength of 6328 Angstroms is 7030 Angstroms.
  • the necessary etch time is on the order of one-half hour and numerous elements can be etched simultaneously. After the pattern of the first mask has been etched into the substrate, any residual photoresist and chromium are stripped away.
  • FIG. 4 is an SEM photograph of the element.
  • the element was designed for use .[.wth.]. .Iadd.with .Iaddend.a HeNe laser of wavelength 6328 Angstroms and is a quartz substrate with a diameter of two inches.
  • the experimentally measured diffraction efficiency of the element was 92%.
  • Other multilevel phase Fresnel zone plates have been made for use with GaAs laser diodes.
  • Fresnel zone plates are, in practice, useful for collimating a monochromatic point source of light.
  • An aspheric conventional lens can perform the same function at considerably higher cost.
  • a spherical lens is significantly less expensive yet cannot achieve perfect collimation. It is, however, possible to take a spherical lens and calcuate from a lens design program the necessary diffractive profile that when etched into a surface of the spherical lens will result in perfect collimation.
  • FIGS. 5a and 5b illustrate aberration correction utilizing the optical elements according to the present invention.
  • FIG. 5a shows an uncorrected spherical aberration pattern produced by a quartz lens when tested with a HeNe laser at 6328 Angstroms. Note that FIG. 5a shows a 150 micron wide point spread function exhibiting classical spherical aberration.
  • FIG. 5b shows the results when the lens includes an eight-phase-level pattern etched into the back surface of a plano-spherically convex quartz lens. The eight-phase-level pattern made using three masks in effect turns a spherical lens into a near-diffraction-limited asphere. Note that the power of the six micron focal point shown in FIG. 5b is increased nearly two hundred-fold over a similar spot in FIG. 5a. Such an optical element will have both refractive and diffractive properties.
  • the disclosed technique can not only correct for spherical aberrations in imperfect optics but for chromatic aberrations as well. All optical materials are dispersive. Dispersion is an undesirable property that must be avoided in broadband optical systems. Generally this is done by balancing the dispersive property of two different optical materials. An achromatic lens is therefore usually a doublet or a triplet lens. This approach leads to expensive and bulky optics. With efficient diffractive optics as disclosed in this patent application chromatic balancing with multiple elements can be avoided altogether.
  • the diffractive focal power of a combined diffractive refractive lens can be used to balance the chromatic dispersion of the conventional lens provided the ratio of the diffractive to refractive focal lengths at the center wavelength is ##EQU4##
  • n c is the index of refraction of the conventional material at the center wavelength
  • ⁇ c is the dispersion constant of the material, i.e., the slope of the index of refraction vs. wavelength curve.
  • FIG. 6 shows this concept,
  • the compensating dispersion is linearly proportional to the focal length of the diffractive component.
  • Curve 20 represents the dispersion due to the bulk dielectric of the conventional lens and curve 22 to the dispersion of the diffractive component.
  • the horizontal axis represents the wavelength bandwidth over which the compensation occurs and the vertical axis represents the optical power (1/F). Adding the optical powers of the refractive and diffractive components together results in curve 24. By satisfying Equation 3, the optical power (and therefore focal length) can be made constant over the wavelength band.
  • Balancing of the chromatic aberration can occur over a very large bandwidth. Its width clearly depends on the used wavelength, the system's application, and on the linearity of the chromaticity of the refractive lens component.
  • FIGS. 7a, b and c show a design comparison of an F/2 silicon lens in the 3-5 micron waveband.
  • FIG. 7a shows the points spread function of a conventional spherical lens.
  • FIG. 7b shows the point spread function of a conventional aspheric lens and
  • FIG. 7c shows the diffraction limited operation when both spherical and chromatic aberration corrections are etched into the surface of a simple spherical lens.
  • FIG. 8 shows a corrected silicon lens made by the multilevel process.
  • a particularly useful embodiment of the present invention is in semiconductor UV lithographic systems where a lack of good transmissive materials (UV grade silica is one of a few) makes conventional broadband chromatic correction nearly impossible. Even microlithography systems based on KrF eximer lasers are severly limited by the lack of suitable UV transmitting achromatic materials. At or below 2500 Angstroms, even fused silica is so dispersive that a few Angstroms bandwidth imposes intolerable chromatic and spherical aberrations.
  • the multilevel structures of the present invention will improve dramatically the capabilities of equipment such as contact printers, projection and proximity wafer printers, step-and-repeaters, microscopes, mask pattern generators, and mask aligners, all of which are based on UV mercury lamp or UV eximer laser optics.
  • the binary corrective patterns for UV lithographic lenses have periodicities and feature sizes that are far larger than the UV wavelength used.
  • a typical projection printer lens may have minimum features in the needed binary pattern of 2-5 microns. Thus, it is feasible to fabricate UV binary lenses, taking into consideration materials and pattern resolution constraints.
  • Present efforts with KrF eximer laser technology are limited to 10 -4 fractional bandwidths. With binary optics chromatic corrections the limits can be extended to 10 -2 . Therefore, the throughput can increase by a factor of 100 with additional benefits of reduced sensitivity to image speckle and dust.
  • Another less obvious benefit of the reduced wavelength is a doubling of depth of focus. This doubling relaxes mechanical alignment tolerances in proximity printers and extends mask lifetimes.
  • the techniques according to the invention can thus be used for etching diffractive profiles into a lens surface to effect chromatic and spherical aberration correction for UV lithographic systems.
  • FIG. 9 shows a lithographic exposure system to reach deep UV for resolving 0.25 micron features.
  • An eximer laser or mercury lamp source 30 illuminates a binary optics column 32 including on the order of 5 or 6 optical elements having the multilevel structures of the invention.
  • the binary optics column 32 replaces conventional optics columns known in prior art lithographic exposure systems. Such conventional columns include many more optical elements than the column 32.
  • one set of masks can be used repeatedly to produce a large number of diffractive optical elements.
  • these diffractive surface profiles can be copied in metal using electroplating techniques.
  • the metal master can then be used to emboss in plastic a large number of replicated optical components.
  • the metal mastering and embossing replication is an established art.

Abstract

The method utilizes high resolution lithography, mask aligning, and reactive ion etching. In particular, at least two binary amplitude masks are generated. A photoresist layer on an optical element substrate is exposed through the first mask and then etched. The process is then repeated for the second and subsequent masks to create a multistep configuration. The resulting optical element is highly efficient.

Description

This is a continuation of copending application Ser. No. 07/399,848, filed on Aug. 29, 1989, and issued on Oct. 20, 1992 as U.S. Pat. No. 5,161,059, which is a divisional of Ser. No. 07/099,307, filed Sep. 21, 1987, and issued on Jan. 23, 1990 as U.S. Pat. No. 4,895,790.
BACKGROUND OF THE INVENTION
This invention relates to high-efficiency, on-axis, multilevel, diffractive optical elements. The high efficiency of these elements allows planar or spherical elements to be diffractively converted to generalized aspheres, and dispersive materials can be diffractively compensated to behave as achromatic materials over broad wavebands. The technique of this disclosure allows ready implementation of this mixed reflective, refractive and diffractive optics in real systems.
The ability to produce arbitrary phase profiles allows for an additional degree of freedom in designing optical systems. Many optical systems now incorporate.[...]. aspheric refractive surfaces to produce such phase profiles. System design is restricted by constraints imposed by factors such as cost, size, and allowable asphericity. Diffractive elements are potentially as versatile and useful as aspheric surfaces and are less expensive, and not as subject to asphericity constraints. Another objective in designing optical systems is to minimize chromatic aberrations. Refractive optical materials are chromatically dispersive. Conventionally, the approach to minimizing chromatic aberrations is to balance the dispersive effects of two different refractive materials. Diffractive surfaces are also wavelength dispersive. It is therefore possible to take a dispersive refractive element, and by placing a diffractive profile on one of its surfaces, produce an element that balances the chromatic effects of the refractive element against the chromatic effects of the diffractive surface. Computer generated diffractive elements have been proposed for numerous applications such as chromatic correction, aberration compensated scanners, and high numerical aperture lenses. A major obstacle to implementing on-axis diffractive elements in actual systems is the, up to now, low diffraction efficiency (<50%).
Theoretically, on-axis diffractive phase elements can achieve 100% diffraction efficiency. To achieve this efficiency, however, a continuous phase profile is necessary. (See, Miyamoto, K., 1961, JOSA 51, 17 and Lesem, L., Hirsch, P., Jordan, J., 1969, IBM J. Res. Dev. 13, 150.) The technology for producing high-quality, high-efficiency, continuous phase profiles does not exist. It has been suggested to quantize the continuous phase profile into discrete phase levels as an approximation to the continuous phase profile. (Goodman, J., Silvestri, A., 1970, IBM J. Res. Dev. 14, 478.) It is known to make such structures using thin-film deposition techniques and material cutting technology. (See, U.K. Patent Application No. 8327520 entitled "Bifocal Contact Lenses Having Diffractive Power".) L. d'Auria et al. in "Photolithographic Fabrication of Thin Film Lenses", OPTICS COMMUNICATIONS, Volume 5, Number 4, July, 1972 discloses a multilevel structure involving successive maskings and etchings of a silicon dioxide layer. Each mask gives only one additional level in the structure and is therefore inefficient. The invention disclosed herein is a method for accurately and reliably making multilevel diffractive surfaces with diffraction efficiencies that can be as high as 99%.
SUMMARY OF THE INVENTION
The method for making high-efficiency, multilevel, diffractive, optical elements according to the invention comprises generating a plurality of binary amplitude masks which include the multilevel phase information. The masks are configured to provide 2N levels where N is the number of masks. The information in each mask is utilized serially for serial etching of the multilevel structures into the optical element. The masks may be made by electron beam lithography and it is preferred that the etching be accomplished by a dry etching technique such as reactive ion etching or ion bombardment. In general, the etching process includes coating the optical element substrate with a photoresist, exposing the photoresist through the masks, developing the photoresist, and etching the substrate. In order to achieve greater than 95% efficiency, three masks and three etching steps are used to produce eight phase levels. An important use of the structures of the invention is in UV lithography.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1a, 1b and 1c are schematic illustrations of Fresnel phase zone plate profiles;
FIG. 2 is a graph of first order diffraction efficiency in a multilevel zone plate as a function of the number of phase levels and fabrication masks;
FIG. 3 is a schematic representation of a binary element fabrication technique disclosed herein;
FIG. 4 is a scanning electron microscope photomicrograph of an eight-level Fresnel zone plate made in accordance with the present invention;
FIGS. 5a and 5b are diffraction patterns showing spherical aberration in an uncorrected and corrected quartz lens, respectively;
FIG. 6 is a graph showing diffractive and refractive dispersion;
FIGS. 7a, b and c are point spread function plots showing diffractive correction of silicon lenses;
FIG. 8 is a photograph of the diffractively corrected silicon lens; and
FIG. 9 is a schematic illustration of a UV lithographic exposure system utilizing the multilevel structures of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1a shows an example of a Fresnel zone plate having a continuous phase profile capable of achieving 100% efficiency. The 2π phase depth corresponds to a material depth of about one micrometer for visible light. Because the technology to produce the continuous phase profile of FIG. 1a does not exist, an approximation to the continuous phase is desirable. FIGS. 1b and 1c show Fresnel phase zone plate profiles quantized to two and four phase levels, respectively. The two-level phase.[.,.]. profile of FIG. 1b results in a diffraction efficiency of 40.5%, and the four-level profile of FIG. 1c results in an efficiency of 81%. For certain optical applications, such discrete phase structures need to achieve a diffraction efficiency of 95% or higher. FIG. 2 shows the diffraction efficiency as a function of the number of discrete phase levels. Eight phase levels achieve 95% efficiency.
The method of the invention accurately and reliably produces multilevel, on-axis, diffractive optical surfaces. Optical elements can be made for use at wavelengths ranging from the ultraviolet to the infrared. These multilevel structures are useful not only for monochromatic light, but also for systems operating with fractional bandwidths as large as 40%. The methods disclosed herein take advantage of technology developed for electronic circuit fabrication such as high resolution lithography, mask aligning, and reactive ion etching. The process for defining the phase profile to be constructed will now be discussed.
Collimated monochromatic light incident on a phase Fresnel zone plate (FIG. 1a) will be diffracted with the light being focused perfectly. The necessary phase profile can be expressed in the simple form ##EQU1## where λ is the wavelength, F the focal length, and φ is evaluated modulo 2π. The phase Fresnel zone plate is an interesting yet limited example of a profile. In general, it is desirable to define arbitrary diffractive phase profiles.
There exist numerous commercially available lens design programs. Many of these programs allow one to describe a general diffractive phase profile on a given surface. The phase profile is described by making an analogy to the optical recording of holographic optical elements. The wavelength and location in space of two coherent point sources are defined and the resulting interference pattern describes the diffractive phase profile. This process describes more general profiles than a simple zone plate, however, which is still a small subset of the possible profiles. In order to make the phase profiles span a much larger set of possibilities, an additional phase term ##EQU2## can be added onto the phase determined from the two point sources. For on-axis phase profiles, the two point sources must lie on the optical axis. Furthermore, if the locations of the two point sources are both set to infinity, then the effect of their interference is null and the phase profile is completely described by the general polynomial expansion of equation (2). One of these general diffractive phase profiles can therefore be placed on any surface of an optical system.
Lens design programs have optimization routines that treat the curvatures of surfaces, the thickness of elements, and the element spacings as variables. Likewise, if a diffractive phase profile is in the system, the optimization routine can treat the polynomial coefficients, anm, as variables. A lens optimization program will determine the optimum coefficients, anm, of the diffractive phase profile for any particular lens systems.
The diffractive phase profile determined by the lens design program and defined by equation (2) contains no information on, how to achieve high diffraction efficiency. Our approach is to take the optimized anm 's and from them define a set of binary amplitude masks. The algorithm for designing these masks is shown in Table 1.
The equation φ(x,y)=C, where C is a constant, describes an equiphase contour. Mask 1 describes the set of equiphase contours that are integer multiple of π. Mask (n=2,3 . . .) describes the set of equiphase contours that are integer multiples of π/2(n-1).
The area between the first two sequential equiphase boundaries is lithographically exposed. The areas between subsequent sequential equiphase boundaries alternate from not being exposed to being exposed. This process is repeated until the total pattern is drawn, covering the full optical aperture.
Table 1 also indicates the phase depth θ to which various lithographic mask patterns are etched. The relationship between phase depth and materials depth d is simply ##EQU3## where n is the refractive index of the optical material. Column 4 of Table 1 indicates the relationship between the number of phase levels k=2N and the number of masks N.
Column 5 indicates the achievable diffraction efficiency η. It is remarkable and an important point of this disclosure that with a mere four masks, 99% diffraction efficiency can be achieved. These binary amplitude masks will then be used in the actual construction of a highly efficient diffractive phase profile.
              TABLE 1                                                     
______________________________________                                    
Multimask Design Algorithm                                                
1 #STR1##                                                                 
      Equi-phase   Phase                                                  
Mask  Boundaries   Etch      # Phase                                      
# N   (l = 0, ±l, ±2, . . . )                                       
                    Depth θ                                         
                             Levels κ                               
                                     % eff · η               
______________________________________                                    
1     φ(x,y) = (l + 1)   2      40.5                                  
      2 #STR2##    2         4      81.0                                  
3                                                                         
      3 #STR3##    4         8      95.0                                  
4                                                                         
      4 #STR4##    8         16     99.0                                  
______________________________________                                    
Three tools necessary for practicing the method of the present invention have been developed over the past ten years by the semiconductor industry. They include sub-micron lithography, ion etchers, and mask aligners. Lithographic pattern generators are capable of drawing binary amplitude masks with feature sizes of 0.1 μm and positioning the features to an even greater accuracy. Reactive ion etchers can etch a binary profile to depths of a few microns with an accuracy on the order of tens of angstroms. Mask aligners are used routinely to align two patterns with an accuracy of fractions of a micron. These are the key technological advances that make it possible to produce high quality diffractive phase profiles.
Electron beam pattern generators produce masks that have binary transmittance profiles. A thin layer of chromium on an optically flat quartz substrate is patterned by e-beam lithography. The input to the e-beam pattern generator is a file stored on a computer tape and properly formatted for the particular machine. For multilevel diffractive elements, the algorithm described in Table 1 defines the patterns to be drawn. The number of phase levels in the final diffractive element constructed from these masks is 2N, where N is the number of masks. For example, only four masks will produce 16 phase level resulting in an efficiency of 99%.
The binary amplitude masks produced from the pattern generator are then used in a serial fashion to construct the multilevel optical element. The fabrication process using the first mask is shown in FIG. 3. An optical substrate 10 such as SiO2 on which the diffractive profile is to reside is coated with a layer of chromium 12 and a layer of photoresist 14. An e-beam generated mask 16 is then placed over the substrate 10 and illuminated with a standard uv photoresist exposure system (not shown). The photoresist layer 14 is then developed resulting in a properly patterned layer of photoresist. The photoresist acts as an etch stop for the reactive ion etching.
Reactive ion etching (RIE) is a process in which an RF electric field excites a gas to produce ions. The ions react with the material of the substrate and etch away the surface at a controlled rate. The reactive ion etching process is anisotropic so that the vertical side walls of the discrete phase profile are retained. Typical RIE etch rates are on the order of 100 Angstroms to 200 Angstroms per minute. As an example, the required first level etch depth for a quartz substrate to be used at a wavelength of 6328 Angstroms is 7030 Angstroms. The necessary etch time is on the order of one-half hour and numerous elements can be etched simultaneously. After the pattern of the first mask has been etched into the substrate, any residual photoresist and chromium are stripped away.
The same procedure outlined above is then repeated on the optical substrate 10, only this time using a second mask and etching to one half the depth of the first etch. For the second and subsequent masks an additional complication arises. These masks have to be accurately aligned to the already existing pattern produced from an earlier etch. Fortunately, the problem of accurately aligning patterns has been solved by the integrated circuit industry. Commercially available mask aligners are capable of aligning two patterns to a fraction of a micron. This accuracy is sufficient to retain diffraction limited performance for the majority of the multilevel structures designed to operate in the visible and infrared.
The simplest example of a diffractive optical element is the Fresnel zone plate described by equation (1). The applicants herein have carried out the above procedure and produced, .[.W.]..Iadd.w.Iaddend.ith three masks, an eight level Fresnel zone plate. FIG. 4 is an SEM photograph of the element. The element was designed for use .[.wth.]. .Iadd.with .Iaddend.a HeNe laser of wavelength 6328 Angstroms and is a quartz substrate with a diameter of two inches. The experimentally measured diffraction efficiency of the element was 92%. Other multilevel phase Fresnel zone plates have been made for use with GaAs laser diodes.
In addition to Fresnel zone plates, the methods of the invention are utilized in making refractive/diffractive combination optical elements. Fresnel zone plates are, in practice, useful for collimating a monochromatic point source of light. An aspheric conventional lens, can perform the same function at considerably higher cost. A spherical lens is significantly less expensive yet cannot achieve perfect collimation. It is, however, possible to take a spherical lens and calcuate from a lens design program the necessary diffractive profile that when etched into a surface of the spherical lens will result in perfect collimation.
FIGS. 5a and 5b illustrate aberration correction utilizing the optical elements according to the present invention. FIG. 5a shows an uncorrected spherical aberration pattern produced by a quartz lens when tested with a HeNe laser at 6328 Angstroms. Note that FIG. 5a shows a 150 micron wide point spread function exhibiting classical spherical aberration. FIG. 5b shows the results when the lens includes an eight-phase-level pattern etched into the back surface of a plano-spherically convex quartz lens. The eight-phase-level pattern made using three masks in effect turns a spherical lens into a near-diffraction-limited asphere. Note that the power of the six micron focal point shown in FIG. 5b is increased nearly two hundred-fold over a similar spot in FIG. 5a. Such an optical element will have both refractive and diffractive properties.
The disclosed technique can not only correct for spherical aberrations in imperfect optics but for chromatic aberrations as well. All optical materials are dispersive. Dispersion is an undesirable property that must be avoided in broadband optical systems. Generally this is done by balancing the dispersive property of two different optical materials. An achromatic lens is therefore usually a doublet or a triplet lens. This approach leads to expensive and bulky optics. With efficient diffractive optics as disclosed in this patent application chromatic balancing with multiple elements can be avoided altogether. The diffractive focal power of a combined diffractive refractive lens can be used to balance the chromatic dispersion of the conventional lens provided the ratio of the diffractive to refractive focal lengths at the center wavelength is ##EQU4## In Equation 3, nc is the index of refraction of the conventional material at the center wavelength, λc, and d is the dispersion constant of the material, i.e., the slope of the index of refraction vs. wavelength curve.
FIG. 6 shows this concept, The compensating dispersion is linearly proportional to the focal length of the diffractive component. Curve 20 represents the dispersion due to the bulk dielectric of the conventional lens and curve 22 to the dispersion of the diffractive component. The horizontal axis represents the wavelength bandwidth over which the compensation occurs and the vertical axis represents the optical power (1/F). Adding the optical powers of the refractive and diffractive components together results in curve 24. By satisfying Equation 3, the optical power (and therefore focal length) can be made constant over the wavelength band.
Balancing of the chromatic aberration can occur over a very large bandwidth. Its width clearly depends on the used wavelength, the system's application, and on the linearity of the chromaticity of the refractive lens component.
FIGS. 7a, b and c show a design comparison of an F/2 silicon lens in the 3-5 micron waveband. FIG. 7a shows the points spread function of a conventional spherical lens. FIG. 7b shows the point spread function of a conventional aspheric lens and FIG. 7c shows the diffraction limited operation when both spherical and chromatic aberration corrections are etched into the surface of a simple spherical lens. FIG. 8 shows a corrected silicon lens made by the multilevel process.
A particularly useful embodiment of the present invention is in semiconductor UV lithographic systems where a lack of good transmissive materials (UV grade silica is one of a few) makes conventional broadband chromatic correction nearly impossible. Even microlithography systems based on KrF eximer lasers are severly limited by the lack of suitable UV transmitting achromatic materials. At or below 2500 Angstroms, even fused silica is so dispersive that a few Angstroms bandwidth imposes intolerable chromatic and spherical aberrations. The multilevel structures of the present invention will improve dramatically the capabilities of equipment such as contact printers, projection and proximity wafer printers, step-and-repeaters, microscopes, mask pattern generators, and mask aligners, all of which are based on UV mercury lamp or UV eximer laser optics. The binary corrective patterns for UV lithographic lenses have periodicities and feature sizes that are far larger than the UV wavelength used. A typical projection printer lens may have minimum features in the needed binary pattern of 2-5 microns. Thus, it is feasible to fabricate UV binary lenses, taking into consideration materials and pattern resolution constraints.
A shift from λ=3500 Angstroms to λ=1900 Angstroms can double circuit density. Present efforts with KrF eximer laser technology are limited to 10-4 fractional bandwidths. With binary optics chromatic corrections the limits can be extended to 10-2. Therefore, the throughput can increase by a factor of 100 with additional benefits of reduced sensitivity to image speckle and dust. Another less obvious benefit of the reduced wavelength is a doubling of depth of focus. This doubling relaxes mechanical alignment tolerances in proximity printers and extends mask lifetimes.
With the technique described in this disclosure a
1) one hundred-fold increase in throughput of lithographically patterned circuitry may be possible;
2) shift into deep UV may increase circuit density by a factor of two; and
3) shift to deep UV will also relax proximity restraints in submicron circuit designs by increasing the depth of focus by as much as 75%. Semiconductor International, May 1987, page 49
All this is possible because of fundamental dielectric materials constraints in purely refractive optical systems are eliminated or relaxed by the diffractive techniques described in this disclosure. The techniques according to the invention can thus be used for etching diffractive profiles into a lens surface to effect chromatic and spherical aberration correction for UV lithographic systems.
FIG. 9 shows a lithographic exposure system to reach deep UV for resolving 0.25 micron features. An eximer laser or mercury lamp source 30 illuminates a binary optics column 32 including on the order of 5 or 6 optical elements having the multilevel structures of the invention. The binary optics column 32 replaces conventional optics columns known in prior art lithographic exposure systems. Such conventional columns include many more optical elements than the column 32.
It should be noted that, as in circuit fabrication process, one set of masks can be used repeatedly to produce a large number of diffractive optical elements. Also, these diffractive surface profiles can be copied in metal using electroplating techniques. The metal master can then be used to emboss in plastic a large number of replicated optical components. The metal mastering and embossing replication is an established art.

Claims (7)

What is claimed is: .[.
1. Method for making high-efficiency, multilevel, diffractive optical elements comprising:
generating at least one binary amplitude mask including multilevel information, the mask being configured to provide 2N levels where N is the number of masks; and
utilizing the masks' information for constructing 2N levels in the optical element, the depths of the levels being related by a fixed ratio..]..[.2. The method of claim 1 wherein the masks are made by lithographic pattern generators..]..[.3. The method of claim 1 including three masks and eight levels..]..[.4. The method of claim 1 wherein the binary amplitude masks are defined by calculating equiphase boundaries utilizing the equation ##EQU5## and the algorithm
______________________________________                                    
             Equi-phase    Phase                                          
             Boundaries    Etch                                           
Mask # N      (l = 0, ± 1, ± 2, . . . )                             
                            Depth θ                                 
______________________________________                                    
1            φ(x,y) = (l + 1)                                         
2                          -                                              
             5 #STR5##     2                                              
             6 #STR6##     4                                              
4                                                                         
             7 #STR7##     8                                              
______________________________________                                    
.].. .[.5. The method of claim 1 wherein the masks are made by electron beam pattern generators..]..[.6. The method of claim 1 wherein the optical element is a lens..]..[.7. The method of claim 1 wherein the optical element corrects for spherical aberration..]..[.8. The method of claim 1 wherein the optical element is corrected for chromatic aberration..]..[.9. Method for making high-efficiency multilevel diffractive optical elements comprising:
making a master optical element according to the method of claim 1; and
using the master optical element to emboss multiple replicated optical components..]..[.10. The method of claim 9 wherein the master optical element is copied in metal which is used for the embossing..]..[.11. Method for making a high efficiency, multi-level, diffractive optical element comprising:
providing a substrate including at least two initial levels;
generating at least one binary amplitude mask including multi-level information; and
utilizing the mask to double the number of levels in the
element..]..Iadd. . A method for making high-efficiency, multilevel, diffractive optical elements comprising:
choosing a desired phase profile for a wavelength λ;
generating at least two binary amplitude masks including multi-level information; and
utilizing said masks to fabricate a diffractive optical element having a number of levels greater than N+1 levels, but no more than 2N levels, where N is the number of masks, said levels approximating said desired phase profile for said wavelength λ in said diffractive optical element. .Iaddend..Iadd.13. The method of claim 12 wherein said optical element is used as a master for replicating optical components in plastic. .Iaddend..Iadd.14. The method of claim 12 wherein said optical element is used as a master optical element which is copied in metal and used for a
replication process. .Iaddend..Iadd.15. A method for making high-efficiency, multilevel, diffractive optical components comprising:
positioning in a replicating apparatus a master generated from at least two binary amplitude masks including multi-level information chosen for a desired phase profile for a wavelength λ and having a number of levels greater than N+1 levels, but no more than 2N levels, where N is the number of masks, said levels in said master approximating said desired phase profile for said wavelength λ in said master;
utilizing said master to replicate the optical components. .Iaddend..Iadd.16. The method of claim 15 wherein said master is a copy of a second diffractive optical element generated from at least two binary amplitude masks including multi-level information and having a number of levels greater than N+1 levels, but no more than 2N levels. .Iaddend..Iadd.17. The method of claim 16 wherein said copy is a metal copy. .Iaddend..Iadd.18. A method for making high-efficiency, multilevel, diffractive optical elements comprising:
generating at least two binary amplitude masks for a bandwidth including multi-level information;
utilizing a first of said binary amplitude masks to fabricate a diffractive optical element having a diffraction efficiency for a wavelength λ within said bandwidth; and
utilizing a second of said binary amplitude masks to increase said diffraction efficiency of said diffractive optical element at said wavelength λ by providing said diffractive optical element with a number of levels greater than N+1 levels, but no more than 2N levels,
where N is the number of masks. .Iaddend..Iadd.19. The method of claim 18 wherein said increased diffraction efficiency from utilizing two masks is at least about 50%. .Iaddend..Iadd.20. The method of claim 18 wherein said step of utilizing a second of said binary amplitude masks further includes aligning said second of said binary amplitude masks with a pattern produced by said utilizing a first of said binary amplitude masks step. .Iaddend..Iadd.21. The method of claim 20 wherein said step of utilizing a second of said binary amplitude masks further includes utilizing said second of said binary amplitude masks to provide an approximation of a continuous phase profile for a wavelength λ in said optical element from said multi-level information of said masks. .Iaddend..Iadd.22. The method of claim 18 wherein at least one of said binary amplitude masks provides an etch depth of no more than π. .Iaddend..Iadd.23. The method of claim 21 wherein said second of said binary amplitude masks provides an etch depth about half of an etch depth of said first of said binary amplitude masks. .Iaddend..Iadd.24. The method of claim 18 wherein said optical element is used as a master for replicating optical components in
plastic. .Iaddend..Iadd.25. The method of claim 18 wherein said optical element is used as a master optical element which is coupled in metal and used for a replication process. .Iaddend..Iadd.26. A method for making high-efficiency, multilevel, diffractive optical elements comprising:
choosing a desired diffractive phase profile for a wavelength λ;
generating at least two binary amplitude masks including multi-level information;
utilizing said masks to fabricate a diffractive optical element having a number of levels greater than N+1, but no more than 2N levels, where N is the number of masks and where at least N+1 of said levels are used to construct said diffractive phase profile. .Iaddend..Iadd.27. A method according to claim 26 wherein said optical element is used as a master for replicating optical components in plastic. .Iaddend..Iadd.28. A method according to claim 26 wherein said optical element is used as a master optical element which is copied in metal and used for a replication process. .Iaddend..Iadd.29. A method for making high-efficiency, multilevel, optical elements comprising:
choosing a desired phase profile for a wavelength λ;
generating N masks including multi-level information; and
utilizing said masks to fabricate an optical element having a number of levels greater than N+1 levels, said levels approximating said desired phase profile for said wavelength λ in said optical element. .Iaddend..Iadd.30. The method of claim 29 wherein said generating step comprises the step of generating said N masks with an electron beam
pattern generator. .Iaddend..Iadd.31. The method of claim 29 wherein said generating step comprises the steps of:
defining a pattern to be drawn on said N masks on a computer; and
producing said N masks on a pattern generator using said defined pattern from said defining step. .Iaddend..Iadd.32. The method of claim 29 wherein said utilizing step further comprises the step of fabricating said optical element as a combined diffractive refractive lens. .Iaddend..Iadd.33. The method of claim 29 wherein said optical element is used as a master for replicating optical components in plastic. .Iaddend..Iadd.34. The method of claim 29 wherein said optical element is used as a master optical element which is copied in metal and used for a replication process. .Iaddend..Iadd.35. The method of claim 29 wherein said N+1 levels are discrete levels. .Iaddend..Iadd.36. The method of claim 29 wherein said masks are binary amplitude masks. .Iaddend..Iadd.37. The method of claim 29 wherein said desired phase profile is an arbitrary phase profile. .Iaddend..Iadd.38. The method of claim 37 wherein said arbitrary phase profile is a generalized asphere. .Iaddend..Iadd.39. The method of claim 29 wherein said desired phase profile is a diffractive phase profile. .Iaddend..Iadd.40. The method of claim 22 wherein said N masks contain
information for at least three levels. .Iaddend..Iadd.41. The method of claim 29 wherein said N masks are generated by lithographic pattern generators. .Iaddend..Iadd.42. The method of claim 29 wherein said optical element is a lens. .Iaddend..Iadd.43. The method of claim 29 wherein said optical element corrects for spherical aberration. .Iaddend..Iadd.44. A method for making high-efficiency, multilevel, optical components comprising:
positioning in a replicating apparatus a master generated from N masks including multi-level information chosen for a desired phase profile for a wavelength λ and having a number of levels greater than N+1 levels, said levels in said master approximating said desired phase profile for said wavelength λ in said master; and
utilizing said master to replicate the optical components. .Iaddend..Iadd.45. A method for making high-efficiency, multilevel, optical elements comprising:
choosing a desired phase profile for a wavelength λ;
generating N masks including multi-level information; and
utilizing said masks to fabricate an optical element having a number of levels greater than N+1 levels but no more than 2N levels, said levels approximating said desired phase profile for said wavelength λ in said optical element. .Iaddend..Iadd.46. A method for making high-efficiency, multilevel, optical components comprising:
positioning in a replicating apparatus a master generated from N masks including multi-level information chosen for a desired phase profile for a wavelength λ and having a number of levels greater than N+1 levels, but no more than 2N levels, said levels in said master approximating said desired phase profile for said wavelength λ in said master;
utilizing said master to replicate the optical components. .Iaddend.
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Publication number Priority date Publication date Assignee Title
US6617188B2 (en) * 2000-03-08 2003-09-09 Ntu Ventures Pte Ltd Quantum well intermixing
US6657208B2 (en) * 2000-06-22 2003-12-02 Koninklijke Philips Electronics N.V. Method of forming optical images, mask for use in this method, method of manufacturing a device using this method, and apparatus for carrying out this method
US20040057107A1 (en) * 2001-11-09 2004-03-25 Xradia, Inc. Reflective lithography mask inspection tool based on achromatic fresnel optics
US20040085641A1 (en) * 2001-11-09 2004-05-06 Xradia, Inc. Achromatic fresnel optics based lithography for short wavelength electromagnetic radiations
US20040247692A1 (en) * 2003-06-03 2004-12-09 Ga-Lane Chen Method for fabricating aspherical lens
US7379151B2 (en) * 2005-07-15 2008-05-27 Canon Kabushiki Kaisha Exposure apparatus comprising cleaning apparatus for cleaning mask with laser beam
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Families Citing this family (137)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5156943A (en) * 1987-10-25 1992-10-20 Whitney Theodore R High resolution imagery systems and methods
GB2269055B (en) * 1992-07-09 1996-06-05 Flat Antenna Co Ltd Phase correcting zone plate
DE59203396D1 (en) * 1992-07-18 1995-09-28 Heidenhain Gmbh Dr Johannes Optical device.
JPH0695354A (en) * 1992-09-10 1994-04-08 Fujitsu Ltd Optical mask
JP3333886B2 (en) * 1992-09-17 2002-10-15 ミノルタ株式会社 Holographic element
US5529936A (en) * 1992-09-30 1996-06-25 Lsi Logic Corporation Method of etching a lens for a semiconductor solid state image sensor
US5340978A (en) * 1992-09-30 1994-08-23 Lsi Logic Corporation Image-sensing display panels with LCD display panel and photosensitive element array
US5760834A (en) * 1992-09-30 1998-06-02 Lsi Logic Electronic camera with binary lens element array
US5737125A (en) * 1992-10-27 1998-04-07 Olympus Optical Co., Ltd. Diffractive optical element and optical system including the same
US5291319A (en) * 1992-12-11 1994-03-01 Xerox Corporation Rotating disc optical synchronization system using binary diffractive optical elements
US5815293A (en) * 1993-02-01 1998-09-29 Matsushita Electric Industrial Co., Ltd. Compound objective lens having two focal points
JPH06331941A (en) * 1993-05-19 1994-12-02 Olympus Optical Co Ltd Projection lens system
US5561558A (en) * 1993-10-18 1996-10-01 Matsushita Electric Industrial Co., Ltd. Diffractive optical device
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US5538674A (en) * 1993-11-19 1996-07-23 Donnelly Corporation Method for reproducing holograms, kinoforms, diffractive optical elements and microstructures
US5543966A (en) * 1993-12-29 1996-08-06 Eastman Kodak Company Hybrid refractive/diffractive achromatic camera lens
US6480334B1 (en) * 1994-01-18 2002-11-12 Massachusetts Institute Of Technology Agile beam steering using phased-array-like elements
US5793600A (en) * 1994-05-16 1998-08-11 Texas Instruments Incorporated Method for forming high dielectric capacitor electrode structure and semiconductor memory devices
US5606434A (en) * 1994-06-30 1997-02-25 University Of North Carolina Achromatic optical system including diffractive optical element
US5623473A (en) * 1994-06-30 1997-04-22 Nikon Corporation Method and apparatus for manufacturing a diffraction grating zone plate
US5519724A (en) * 1994-08-02 1996-05-21 Panasonic Technologies, Inc. Multiwavelength and multibeam diffractive optics system for material processing
US6073846A (en) * 1994-08-17 2000-06-13 Metrologic Instruments, Inc. Holographic laser scanning system and process and apparatus and method
US5847877A (en) * 1994-09-12 1998-12-08 Olympus Optical Co., Ltd. Diffractive optical element
US5559338A (en) * 1994-10-04 1996-09-24 Excimer Laser Systems, Inc. Deep ultraviolet optical imaging system for microlithography and/or microfabrication
US6392806B2 (en) * 1994-10-27 2002-05-21 Kopin Corporation Efficient illumination system for color projection displays
US6560018B1 (en) 1994-10-27 2003-05-06 Massachusetts Institute Of Technology Illumination system for transmissive light valve displays
US6417967B1 (en) * 1994-10-27 2002-07-09 Massachusetts Institute Of Technology System and method for efficient illumination in color projection displays
US5781257A (en) * 1995-01-30 1998-07-14 Lockheed Martin Missiles & Space Co Flat panel display
US5600486A (en) * 1995-01-30 1997-02-04 Lockheed Missiles And Space Company, Inc. Color separation microlens
US5728324A (en) * 1995-01-31 1998-03-17 Digital Optics Corporation Molding diffractive optical elements
US6911638B2 (en) * 1995-02-03 2005-06-28 The Regents Of The University Of Colorado, A Body Corporate Wavefront coding zoom lens imaging systems
US20020195548A1 (en) * 2001-06-06 2002-12-26 Dowski Edward Raymond Wavefront coding interference contrast imaging systems
US20020118457A1 (en) * 2000-12-22 2002-08-29 Dowski Edward Raymond Wavefront coded imaging systems
US7218448B1 (en) * 1997-03-17 2007-05-15 The Regents Of The University Of Colorado Extended depth of field optical systems
US6778326B1 (en) * 1995-03-29 2004-08-17 Eastman Kodak Company Combined heat filter and condenser lens, a projection type apparatus using such, and a method for fabricating it
US5694230A (en) * 1995-06-07 1997-12-02 Digital Optics Corp. Diffractive optical elements as combiners
US5734155A (en) * 1995-06-07 1998-03-31 Lsi Logic Corporation Photo-sensitive semiconductor integrated circuit substrate and systems containing the same
IL115295A0 (en) * 1995-09-14 1996-12-05 Yeda Res & Dev Multilevel diffractive optical element
US5706139A (en) * 1995-10-17 1998-01-06 Kelly; Shawn L. High fidelity optical system for electronic imaging
JPH09167731A (en) * 1995-12-14 1997-06-24 Mitsubishi Electric Corp Projection aligner, mask pattern for evaluating aberration, method for evaluating aberration, filter for removing aberration and production of semiconductor device
US5770889A (en) * 1995-12-29 1998-06-23 Lsi Logic Corporation Systems having advanced pre-formed planar structures
GB9600469D0 (en) 1996-01-10 1996-03-13 Secr Defence Three dimensional etching process
US5684631A (en) * 1996-05-13 1997-11-04 Lucent Technologies Inc. Optical modulator/switch including reflective zone plate and related method of use
US6008941A (en) * 1996-06-25 1999-12-28 Digital Optics Corporation Optical soft aperture and use thereof
US5718496A (en) * 1996-06-25 1998-02-17 Digital Optics Corporation Projection pointer
US5864381A (en) * 1996-07-10 1999-01-26 Sandia Corporation Automated pupil remapping with binary optics
DE69734675T2 (en) * 1996-08-29 2006-06-14 Corning Inc METHOD FOR DETERMINING LASER-INDUCED COMPACTING IN MELTED QUARTZ
US20080136955A1 (en) * 1996-09-27 2008-06-12 Tessera North America. Integrated camera and associated methods
US6235141B1 (en) * 1996-09-27 2001-05-22 Digital Optics Corporation Method of mass producing and packaging integrated optical subsystems
US6128134A (en) * 1997-08-27 2000-10-03 Digital Optics Corporation Integrated beam shaper and use thereof
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JP3287236B2 (en) * 1996-10-03 2002-06-04 キヤノン株式会社 Manufacturing method of diffractive optical element
US6829091B2 (en) * 1997-02-07 2004-12-07 Canon Kabushiki Kaisha Optical system and optical instrument with diffractive optical element
US5779751A (en) * 1997-03-14 1998-07-14 Xerox Corporation Photolithographic method of fabricating fresnel lenses
US5815327A (en) * 1997-03-14 1998-09-29 Xerox Corporation Photolithographic method of fabricating fresnel lenses
JPH10293205A (en) * 1997-04-18 1998-11-04 Minolta Co Ltd Diffraction type optical element and manufacture of die
US6002520A (en) * 1997-04-25 1999-12-14 Hewlett-Packard Company Illumination system for creating a desired irradiance profile using diffractive optical elements
JPH10339804A (en) 1997-06-06 1998-12-22 Canon Inc Diffraction optical element and optical axis adjusting device therefor
US6055107A (en) * 1997-08-12 2000-04-25 Industrial Technology Research Institute Diffractive lens and preparation method thereof
US6285503B1 (en) * 1997-08-25 2001-09-04 Industrial Technology Research Institute Holographic diffuser
US6475704B1 (en) * 1997-09-12 2002-11-05 Canon Kabushiki Kaisha Method for forming fine structure
TW582549U (en) * 1997-09-24 2004-04-01 Matsushita Electric Ind Co Ltd Calculating apparatus of diffraction efficiency of diffraction lens, lens with optical grating device and reading optical system
US6567226B2 (en) * 1998-03-03 2003-05-20 Sumitomo Electric Industries, Ltd. Method for designing a refractive or reflective optical system and method for designing a diffraction optical element
US6040943A (en) * 1998-03-23 2000-03-21 Donnelly Optics Digital camera objective with diffractive optical surface
US6069738A (en) * 1998-05-27 2000-05-30 University Technology Corporation Apparatus and methods for extending depth of field in image projection systems
US6410213B1 (en) 1998-06-09 2002-06-25 Corning Incorporated Method for making optical microstructures having profile heights exceeding fifteen microns
US6052230A (en) * 1998-07-10 2000-04-18 Northrop Grumman Corporation Optical blurring filter which is resistant to digital image restoration
JP2000098116A (en) * 1998-09-18 2000-04-07 Canon Inc Element or manufacture of mold for manufacturing element
JP3359309B2 (en) * 1998-10-29 2002-12-24 キヤノン株式会社 Method for manufacturing binary diffractive optical element
US6856392B1 (en) * 1998-11-09 2005-02-15 Canon Kabushiki Kaisha Optical element with alignment mark, and optical system having such optical element
JP3995813B2 (en) * 1998-12-09 2007-10-24 ペンタックス株式会社 Diffraction lens design method
US6187211B1 (en) * 1998-12-15 2001-02-13 Xerox Corporation Method for fabrication of multi-step structures using embedded etch stop layers
JP2002532893A (en) 1998-12-17 2002-10-02 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Light engine
WO2000062103A1 (en) * 1999-04-14 2000-10-19 Kan Cheng Fresnel zone plate comprised entirely of transparent constructive zones
US6881358B1 (en) * 1999-07-06 2005-04-19 Mems Optical Inc. Mold apparatus and method
DE19961970A1 (en) * 1999-12-22 2001-06-28 Deutsche Telekom Ag Production of optical switches comprises electrolytically etching nanostructured regions made of doped semiconductor material
JP2001235611A (en) * 2000-02-25 2001-08-31 Shimadzu Corp Holographic grating
WO2001065305A1 (en) * 2000-03-01 2001-09-07 Kan Cheng Fresnel zone plate with multiple layers of delay zones
GB2360604A (en) * 2000-03-20 2001-09-26 Vision Eng Diffractive optical element
US6536898B1 (en) * 2000-09-15 2003-03-25 The Regents Of The University Of Colorado Extended depth of field optics for human vision
EP1330665A1 (en) * 2000-10-31 2003-07-30 Corning Incorporated Optical lithography and a method of inducing transmission in optical lithography preforms
US6915665B2 (en) * 2000-10-31 2005-07-12 Corning Incorporated Method of inducing transmission in optical lithography preforms
RU2179336C1 (en) * 2000-12-26 2002-02-10 Общество С Ограниченной Ответственностью "Инсмат Технология" Method and device for shaping optical image in incoherent light (alternatives)
US6873733B2 (en) 2001-01-19 2005-03-29 The Regents Of The University Of Colorado Combined wavefront coding and amplitude contrast imaging systems
US6890834B2 (en) * 2001-06-11 2005-05-10 Matsushita Electric Industrial Co., Ltd. Electronic device and method for manufacturing the same
US6842297B2 (en) 2001-08-31 2005-01-11 Cdm Optics, Inc. Wavefront coding optics
CN1313846C (en) * 2001-10-05 2007-05-02 松下电器产业株式会社 Diffraction optical element and optical head with the diffraction optical element
US6905618B2 (en) * 2002-07-30 2005-06-14 Agilent Technologies, Inc. Diffractive optical elements and methods of making the same
AU2003279122A1 (en) * 2002-10-03 2004-04-23 Massachusetts Insitute Of Technology System and method for holographic fabrication and replication of diffractive optical elements for maskless lithography
US20040161709A1 (en) * 2003-02-10 2004-08-19 Schroeder Joseph F. Laser-written optical structures within calcium fluoride and other crystal materials
US7401984B2 (en) * 2003-05-16 2008-07-22 Hoya Corporation Optical connector
CN100508074C (en) 2003-05-30 2009-07-01 Cdm光学有限公司 Lithographic systems and methods with extended depth of focus
US20040263978A1 (en) * 2003-06-18 2004-12-30 Chipper Robert B. Method and apparatus for forming an image using only diffractive optics
US20070110361A1 (en) * 2003-08-26 2007-05-17 Digital Optics Corporation Wafer level integration of multiple optical elements
US7611244B2 (en) * 2003-11-20 2009-11-03 Heidelberg Engineering Gmbh Adaptive optics for compensating for optical aberrations in an imaging process
US20050190811A1 (en) * 2004-02-26 2005-09-01 Gruhlke Russell W. External cavity laser and method for selectively emitting light based on wavelength using aberration-corrected focusing diffractive optical element
US20060029889A1 (en) * 2004-08-06 2006-02-09 Wang Tak K Method to fabricate diffractive optics
KR20070042212A (en) * 2004-09-07 2007-04-20 코닌클리케 필립스 일렉트로닉스 엔.브이. Optical device with fresnel structure
US7207700B2 (en) * 2005-09-22 2007-04-24 Visteon Global Technologies, Inc. Near field lens with spread characteristics
US7401948B2 (en) 2005-10-17 2008-07-22 Visteon Global Technologies, Inc. Near field lens having reduced size
US7160010B1 (en) 2005-11-15 2007-01-09 Visteon Global Technologies, Inc. Light manifold for automotive light module
US7489453B2 (en) 2005-11-15 2009-02-10 Visteon Global Technologies, Inc. Side emitting near field lens
US7564070B2 (en) 2005-11-23 2009-07-21 Visteon Global Technologies, Inc. Light emitting diode device having a shield and/or filter
US7438454B2 (en) 2005-11-29 2008-10-21 Visteon Global Technologies, Inc. Light assembly for automotive lighting applications
US7656345B2 (en) 2006-06-13 2010-02-02 Ball Aerospace & Technoloiges Corp. Low-profile lens method and apparatus for mechanical steering of aperture antennas
US7554742B2 (en) 2007-04-17 2009-06-30 Visteon Global Technologies, Inc. Lens assembly
US7813054B2 (en) * 2007-12-14 2010-10-12 Rpc Photonics, Inc. Optical elements with saddle shaped structures for diffusing or shaping light
US8669461B2 (en) * 2008-10-17 2014-03-11 Massachusetts Institute Of Technology Ultra-high efficiency multi-junction solar cells using polychromatic diffractive concentrators
US8049963B2 (en) * 2008-10-17 2011-11-01 Massachusetts Institute Of Technology Multiple-wavelength binary diffractive lenses
US20100177390A1 (en) * 2008-12-03 2010-07-15 Robert Hutchins Wavelength dependent optical elements and applications thereof
US8383512B2 (en) 2011-01-19 2013-02-26 Macronix International Co., Ltd. Method for making multilayer connection structure
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US9048341B2 (en) 2011-03-16 2015-06-02 Macronix International Co., Ltd. Integrated circuit capacitor and method
US9070447B2 (en) 2013-09-26 2015-06-30 Macronix International Co., Ltd. Contact structure and forming method
US9196628B1 (en) 2014-05-08 2015-11-24 Macronix International Co., Ltd. 3D stacked IC device with stepped substack interlayer connectors
US9356040B2 (en) 2014-06-27 2016-05-31 Macronix International Co., Ltd. Junction formation for vertical gate 3D NAND memory
DE102014219663A1 (en) * 2014-09-29 2016-03-31 Ihp Gmbh - Innovations For High Performance Microelectronics / Leibniz-Institut Für Innovative Mikroelektronik Photonically integrated chip, optical component with photonically integrated chip and method for its production
US9379129B1 (en) 2015-04-13 2016-06-28 Macronix International Co., Ltd. Assist gate structures for three-dimensional (3D) vertical gate array memory structure
US9478259B1 (en) 2015-05-05 2016-10-25 Macronix International Co., Ltd. 3D voltage switching transistors for 3D vertical gate memory array
US9910276B2 (en) 2015-06-30 2018-03-06 Microsoft Technology Licensing, Llc Diffractive optical elements with graded edges
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Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3586412A (en) * 1968-05-20 1971-06-22 Battelle Development Corp Holographic lens with aberration correction
US3726732A (en) * 1970-07-09 1973-04-10 Franklin Mint Inc Multi-step etching projection system
US4155627A (en) * 1976-02-02 1979-05-22 Rca Corporation Color diffractive subtractive filter master recording comprising a plurality of superposed two-level relief patterns on the surface of a substrate
US4252891A (en) * 1977-07-29 1981-02-24 Kostyshin Maxim T Method of manufacturing embossed articles of preset configuration
US4327171A (en) * 1976-05-28 1982-04-27 Stanley Poler Method of making an intra-ocular lens-mount element
US4414059A (en) * 1982-12-09 1983-11-08 International Business Machines Corporation Far UV patterning of resist materials
JPS58209123A (en) * 1982-05-31 1983-12-06 Nippon Telegr & Teleph Corp <Ntt> Processing method for substrate
US4434224A (en) * 1981-02-06 1984-02-28 Nippon Telegraph & Telephone Public Corp. Method of pattern formation
GB2129157A (en) * 1982-10-27 1984-05-10 Pilkington Perkin Elmer Ltd Bifocal contact lenses having defractive power
US4564584A (en) * 1983-12-30 1986-01-14 Ibm Corporation Photoresist lift-off process for fabricating semiconductor devices
US4579812A (en) * 1984-02-03 1986-04-01 Advanced Micro Devices, Inc. Process for forming slots of different types in self-aligned relationship using a latent image mask
US4632898A (en) * 1985-04-15 1986-12-30 Eastman Kodak Company Process for fabricating glass tooling
US4690880A (en) * 1984-07-20 1987-09-01 Canon Kabushiki Kaisha Pattern forming method
US4724043A (en) * 1984-09-04 1988-02-09 International Business Machines Corporation Process for forming a master mold for optical storage disks
US4737447A (en) * 1983-11-11 1988-04-12 Pioneer Electronic Corporation Process for producing micro Fresnel lens
US4810621A (en) * 1985-11-18 1989-03-07 The Perkin-Elmer Corporation Contact lithographic fabrication of patterns on large optics
US4895790A (en) * 1987-09-21 1990-01-23 Massachusetts Institute Of Technology High-efficiency, multilevel, diffractive optical elements
US4936665A (en) * 1987-10-25 1990-06-26 Whitney Theodore R High resolution imagery systems and methods

Patent Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3586412A (en) * 1968-05-20 1971-06-22 Battelle Development Corp Holographic lens with aberration correction
US3726732A (en) * 1970-07-09 1973-04-10 Franklin Mint Inc Multi-step etching projection system
US4155627A (en) * 1976-02-02 1979-05-22 Rca Corporation Color diffractive subtractive filter master recording comprising a plurality of superposed two-level relief patterns on the surface of a substrate
US4327171A (en) * 1976-05-28 1982-04-27 Stanley Poler Method of making an intra-ocular lens-mount element
US4252891A (en) * 1977-07-29 1981-02-24 Kostyshin Maxim T Method of manufacturing embossed articles of preset configuration
US4434224A (en) * 1981-02-06 1984-02-28 Nippon Telegraph & Telephone Public Corp. Method of pattern formation
JPS58209123A (en) * 1982-05-31 1983-12-06 Nippon Telegr & Teleph Corp <Ntt> Processing method for substrate
GB2129157A (en) * 1982-10-27 1984-05-10 Pilkington Perkin Elmer Ltd Bifocal contact lenses having defractive power
US4414059A (en) * 1982-12-09 1983-11-08 International Business Machines Corporation Far UV patterning of resist materials
US4737447A (en) * 1983-11-11 1988-04-12 Pioneer Electronic Corporation Process for producing micro Fresnel lens
US4564584A (en) * 1983-12-30 1986-01-14 Ibm Corporation Photoresist lift-off process for fabricating semiconductor devices
US4579812A (en) * 1984-02-03 1986-04-01 Advanced Micro Devices, Inc. Process for forming slots of different types in self-aligned relationship using a latent image mask
US4690880A (en) * 1984-07-20 1987-09-01 Canon Kabushiki Kaisha Pattern forming method
US4724043A (en) * 1984-09-04 1988-02-09 International Business Machines Corporation Process for forming a master mold for optical storage disks
US4632898A (en) * 1985-04-15 1986-12-30 Eastman Kodak Company Process for fabricating glass tooling
US4810621A (en) * 1985-11-18 1989-03-07 The Perkin-Elmer Corporation Contact lithographic fabrication of patterns on large optics
US4895790A (en) * 1987-09-21 1990-01-23 Massachusetts Institute Of Technology High-efficiency, multilevel, diffractive optical elements
US4936665A (en) * 1987-10-25 1990-06-26 Whitney Theodore R High resolution imagery systems and methods

Non-Patent Citations (18)

* Cited by examiner, † Cited by third party
Title
Burggraaf, "Excimer Laser Lithography" Semiconductor International, May 1987, pp. 49-50.
Burggraaf, Excimer Laser Lithography Semiconductor International, May 1987, pp. 49 50. *
d Auria, et al., Optics Comm., vol. 5, No. 4, Jul. 1972, pp. 232 235. *
d'Auria, et al., Optics Comm., vol. 5, No. 4, Jul. 1972, pp. 232-235.
Goodman, et al., "Some Effects of Fourier-Domain Phase Quantization", IBM J. Res. Develop., Sep. 1970, pp. 478-484.
Goodman, et al., Some Effects of Fourier Domain Phase Quantization , IBM J. Res. Develop., Sep. 1970, pp. 478 484. *
Koronkevich, et al., "Fabrication of Kinoform Optical Elements" Optik, vol. 67, No. 3, 1984, pp. 257-265.
Koronkevich, et al., Fabrication of Kinoform Optical Elements Optik, vol. 67, No. 3, 1984, pp. 257 265. *
Lesem, et al. "The Kinoform: A New Wavefront Reconstruction Device", IBM J. Res. Development, Mar. 1969, pp. 150-155.
Lesem, et al. The Kinoform: A New Wavefront Reconstruction Device , IBM J. Res. Development, Mar. 1969, pp. 150 155. *
Mikhaltsova, et al., "Kinoform Axicons", Optik, vol. 67, No. 3, 1984, pp. 267-277.
Mikhaltsova, et al., Kinoform Axicons , Optik, vol. 67, No. 3, 1984, pp. 267 277. *
Miyamoto, "The Phase Fresnel Lens", J. Optical Soc. Amer., vol. 51, No. 1, Jan. 1961, pp. 17-20.
Miyamoto, The Phase Fresnel Lens , J. Optical Soc. Amer., vol. 51, No. 1, Jan. 1961, pp. 17 20. *
Sonek, et al., "Ultraviolet Grating Polarizers", J. Vac. Sci. Technol., vol. 19, No. 4, Nov./Dec. 1981 pp. 921-923.
Sonek, et al., Ultraviolet Grating Polarizers , J. Vac. Sci. Technol., vol. 19, No. 4, Nov./Dec. 1981 pp. 921 923. *
Vannuci, "A `Tuned` Fresnel Lens", Appl. Optics, vol. 25, No. 10, Aug. 15, 1986, pp. 2831-2834.
Vannuci, A Tuned Fresnel Lens , Appl. Optics, vol. 25, No. 10, Aug. 15, 1986, pp. 2831 2834. *

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* Cited by examiner, † Cited by third party
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US6657208B2 (en) * 2000-06-22 2003-12-02 Koninklijke Philips Electronics N.V. Method of forming optical images, mask for use in this method, method of manufacturing a device using this method, and apparatus for carrying out this method
US20040057107A1 (en) * 2001-11-09 2004-03-25 Xradia, Inc. Reflective lithography mask inspection tool based on achromatic fresnel optics
US20040085641A1 (en) * 2001-11-09 2004-05-06 Xradia, Inc. Achromatic fresnel optics based lithography for short wavelength electromagnetic radiations
US6914723B2 (en) * 2001-11-09 2005-07-05 Xradia, Inc. Reflective lithography mask inspection tool based on achromatic Fresnel optics
US20050168820A1 (en) * 2001-11-09 2005-08-04 Xradia, Inc. Achromatic fresnel optics for ultraviolet and x-ray radiation
US20040247692A1 (en) * 2003-06-03 2004-12-09 Ga-Lane Chen Method for fabricating aspherical lens
US7379151B2 (en) * 2005-07-15 2008-05-27 Canon Kabushiki Kaisha Exposure apparatus comprising cleaning apparatus for cleaning mask with laser beam
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