US20040197972A1 - Multi-pattern shadow mask system for laser annealing - Google Patents

Multi-pattern shadow mask system for laser annealing Download PDF

Info

Publication number
US20040197972A1
US20040197972A1 US10/831,443 US83144304A US2004197972A1 US 20040197972 A1 US20040197972 A1 US 20040197972A1 US 83144304 A US83144304 A US 83144304A US 2004197972 A1 US2004197972 A1 US 2004197972A1
Authority
US
United States
Prior art keywords
section
mask
aperture
shadow mask
laser annealing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/831,443
Inventor
Masahiro Adachi
Apostolos Voutsas
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sharp Laboratories of America Inc
Original Assignee
Sharp Laboratories of America Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sharp Laboratories of America Inc filed Critical Sharp Laboratories of America Inc
Priority to US10/831,443 priority Critical patent/US20040197972A1/en
Publication of US20040197972A1 publication Critical patent/US20040197972A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/064Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
    • B23K26/066Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms by using masks
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/26Bombardment with radiation
    • H01L21/263Bombardment with radiation with high-energy radiation
    • H01L21/268Bombardment with radiation with high-energy radiation using electromagnetic radiation, e.g. laser radiation
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/324Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/66007Multistep manufacturing processes
    • H01L29/66075Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
    • H01L29/66227Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
    • H01L29/66409Unipolar field-effect transistors
    • H01L29/66477Unipolar field-effect transistors with an insulated gate, i.e. MISFET
    • H01L29/66742Thin film unipolar transistors
    • H01L29/6675Amorphous silicon or polysilicon transistors
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/12Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body
    • H01L27/1214Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
    • H01L27/1259Multistep manufacturing methods
    • H01L27/127Multistep manufacturing methods with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
    • H01L27/1274Multistep manufacturing methods with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement using crystallisation of amorphous semiconductor or recrystallisation of crystalline semiconductor
    • H01L27/1285Multistep manufacturing methods with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement using crystallisation of amorphous semiconductor or recrystallisation of crystalline semiconductor using control of the annealing or irradiation parameters, e.g. using different scanning direction or intensity for different transistors

Definitions

  • This invention generally relates to the fabrication of thin film transistors (TFTs) for liquid crystal displays (LCDs) and, more particularly, to a system and method for using a shadow mask for the laser annealing of silicon substrates, to form precisely located polysilicon or single crystal active regions.
  • TFTs thin film transistors
  • LCDs liquid crystal displays
  • the TFTs used in LCD active layer are made from either polycrystalline or single grain crystalline silicon (Si) films that are crystallized in response to laser annealing an amorphous silicon precursor film. These TFTs are used to form pixel switching devices, and/or LCD peripheral circuits, and/or electro-luminescence displays. They are also used in the fabrication of various integrated circuits like sensor arrays on a glass substrate.
  • TFT poly-Si thin film transistors
  • the quality of poly-Si (polycrystallized silicon) film that is the semiconductor layer of the transistors is one of the most important factors in the formation of TFTs, and directly affects the circuit performance.
  • Poly-Si films typically consist of crystal grains and boundaries between the grains. The grains often include crystal defects.
  • One approach for the improvement of the poly-Si film quality is in the use of a laser annealing method that can crystallize amorphous silicon precursor into a poly-Si film with fewer intra-grain defects.
  • High-performance TFTs require high electron mobility through the transistor channel region.
  • One TFT fabrication problem is in the control of these channel locations on the substrate. That is, the channels must be located in predetermined substrate areas that are formed from either polycrystalline of single crystal material. Likewise, the orientation, or “direction” of the transistor channel is important when fitting the channel regions inside polycrystalline regions.
  • the best performing TFTs have channel regions are formed in the localized high quality poly-Si area, with channels formed in a direction parallel to the lateral growth.
  • a semiconductor material having regular, quasi-regular, or single-crystal structure can be made by a technique involving localized irradiation of the film with one or several pulses of a beam of laser radiation.
  • a patterned projection mask defines the localized irradiation of the laser beam.
  • the technique can be used in the manufacture of high-speed liquid crystal display devises, wherein pixel switches or/and driver circuitry are made in single-crystal or regular polycrystalline films.
  • transistor channels could be defined more precisely in predetermined polycrystalline, or single crystal substrate regions.
  • the present invention laser annealing system and method features the use of a shadow mask for the patterned projection of a laser beam.
  • the mask is divided into block patterns called sections.
  • the mask has the capability of making alignment marks for the exposure equipment that permits precision alignment.
  • the mask also permits multi-shot laser irradiation. Because of these features, the present invention laser annealing apparatus is able to supply higher performance TFTs and higher yields.
  • the apparatus can control the location and direction of the localized high quality poly-Si area, to match to the layout design (formation) of the TFT channel regions.
  • the present invention shadow mask includes a plurality of sections with the different aperture patterns, corresponding the layout design of the poly-Si TFT channel regions.
  • Some aperture patterns are designed to form a seed portion of the poly-Si material that is grown laterally by stepping the position of the laser beam, through the same aperture pattern, across the-substrate.
  • Other aperture patterns form an alignment mark that is used by the exposure apparatus to precisely define the location of poly-Si islands and localized high quality poly-Si areas.
  • the irradiation can be done with plurality of shots per at the same substrate position through an area of the patterned projection mask to avoid the defects of the poly-Si film caused by the fluctuation in the power of laser beam.
  • a multi-pattern shadow mask method for laser annealing, the method comprises: supplying a silicon substrate; supplying a multi-pattern shadow mask with a plurality of aperture patterns; creating substrate alignment marks; with respect to the alignment marks, laser annealing a substrate region in a plurality of aperture patterns; forming a corresponding plurality of polysilicon regions; and, forming a corresponding plurality of transistor channel regions in the plurality of polysilicon regions.
  • laser annealing in a plurality of aperture patterns includes: laser annealing a first area in a substrate region with a first aperture pattern; and, step-and-repeat laser annealing in a second area, adjacent the first area, in the substrate region. Then, forming a corresponding plurality of polycrystalline regions includes laterally growing crystals in response to the step-and-repeat laser annealing process.
  • the shadow mask includes a plurality of sections, with each section having at least one aperture pattern.
  • a shadow mask section can be selected to create a corresponding aperture pattern. If the mask section includes a plurality of aperture patterns, the selection of mask section creates all the corresponding aperture patterns in the selected section.
  • using the shadow mask to create the plurality of aperture patterns includes: selecting a first mask section with a plurality of aperture patterns; using the alignment marks, aligning the substrate with the first mask; using the first mask section to step-and repeat laser anneal regions in the substrate with the plurality of aperture patterns; selecting a second mask section with a plurality of aperture patterns; using the alignment marks, aligning the substrate with the second mask; using the second mask section to step-and repeat laser anneal regions in the substrate with the plurality of aperture patterns.
  • forming polycrystalline regions in a plurality of patterns includes: forming a plurality of polycrystalline patterns in response to laser annealing with the first mask section; and, forming a plurality of polycrystalline patterns in response to laser annealing with the second mask section.
  • FIGS. 1 a through 1 c are plan views of an exemplary present invention multi-pattern shadow mask.
  • FIG. 2 is a perspective view of the present invention multi-pattern shadow mask laser annealing system.
  • FIGS. 3 a through 3 c are diagrams illustrating the use of different mask sections to promote lateral growth in transverse directions.
  • FIGS. 4 and 5 illustrate the mask registration section in detail and the resultant alignment mark formed in a substrate, in response to using the registration section.
  • FIG. 6 is a plan view of a liquid crystal display substrate with a plurality of panels, of which the first panel is exemplary.
  • FIG. 7 is a detailed depiction of the first panel of FIG. 6.
  • FIG. 8 is a flowchart illustrating the present invention multi-pattern shadow mask method for laser annealing.
  • FIGS. 1 a through 1 c are plan views of an exemplary present invention multi-pattern shadow mask.
  • the mask 100 comprises a plurality of shadow mask sections with apertures. Shown are sections 102 , 104 , 106 , 108 , 110 , 112 , 114 , and 116 . Each section includes at least one substrate alignment aperture.
  • mask section 106 includes at least two aperture patterns.
  • aperture pattern 118 is shown in detail.
  • FIG. 1 c shows aperture pattern 120 of mask section 108 is detail.
  • the mask 100 includes a plurality of laser annealing aperture patterns and that each mask section includes at least one pattern of apertures. As in section 106 for example, each section often includes apertures in a plurality of patterns.
  • each mask section is defined as a rectangle with a length and width.
  • mask section 114 is shown as having a length 122 and a width 124 .
  • the present invention mask sections are not limited to any particular shape. It is also typical to transversely locate the rectangular mask sections on the mask 100 .
  • mask section 112 is transversely located, or perpendicular to mask section 114 .
  • the shadow mask 100 includes at least one registration section with at least one substrate alignment aperture for forming a position reference mark on a substrate.
  • the shadow mask 100 includes at least two corners, with a first registration section 126 formed in a first mask corner and a second registration section 128 formed in a second mask corner.
  • the aperture pattern shown is a cross shape. However, the registration section need not be placed in the corners of the mask 100 , and the aperture pattern need not necessarily be shaped as shown.
  • mask section 106 includes aperture pattern 118 formed as a rectangle with a first length 130 and first width 132 .
  • mask section 108 includes aperture pattern 120 formed as a rectangle with a second length 134 and a second width 136 .
  • Aperture pattern 120 can be considered to be transversely located with respect to the first aperture 118 (see FIG. 1 b ). That is, the length 134 is perpendicular to length 130 .
  • FIG. 2 is a perspective view of the present invention multi-pattern shadow mask laser annealing system.
  • the system 200 comprises a laser and associated optics system (not shown) to supply a laser beam that is represented by reference designator 202 . Also shown is a shadow mask 100 , as described in detail above.
  • a lens 203 projects the laser beam after it passes through the mask apertures.
  • the laser supplies a beam 202 which can be defined as a rectangle with a length 204 and a width 206 .
  • the length 204 and width 206 of the beam match the length ( 122 ) and width ( 124 ) of the mask sections (see FIG. 1 a ).
  • the beam dimensions need not necessarily match the mask section dimensions, but a close match promotes efficiency.
  • the laser is capable of transverse movement to supply a beam in a first orientation (as shown) with respect to the shadow mask, and a second orientation (not shown), transverse to the first orientation.
  • This transverse movement permits the laser beam 202 to be moved over transversely oriented mask sections. If the mask includes no transverse sections, the laser beam need not be capable of transverse movement.
  • a silicon substrate 210 with a plurality of typically rectangular substrate regions. These regions are seen as panels in FIG. 6, described below. Alignment marks 212 and 214 are formed in at least two of the corners of each substrate region 216 (see FIG. 1 a , reference designators 126 and 128 ). A plurality of polycrystalline patterns are formed in the substrate region 216 in response to laser annealing with one of the shadow mask sections. As described in more detail below, the substrate includes polycrystalline patterns laterally grown in a first direction in response to the first mask first aperture pattern and polycrystalline pattern laterally grown in a second direction, transverse to the first direction, in response to the second mask section second aperture pattern.
  • a Si precursor film preferably amorphous Si film deposited by a plasma CVD (Chemical Vapor Deposition) having a thickness of 50 nanometers (nm) is formed over a protective layer (not shown) on a glass, quartz, or plastic substrate (not shown).
  • the protective layer is typically a silicon oxide film having a thickness of 500 nm.
  • the laser beam irradiates a section of the shadow mask and the aperture pattern of the mask is projected through the lens on the Si precursor film.
  • the laser beam can be generated by a XeCl excimer laser.
  • the optical system has capability of rotating at least 90 degrees.
  • the projection optical system is shown as a lens, but it can be an equivalent projection or a beautiful projection system. In the case of an equivalent projection system, the energy density of the laser may be great enough to damage to the shadow mask. Therefore, a durable mask material must be used, or a technique of beam splitting and re-synthesis before and after irradiation of the mask is required.
  • the shadow mask has a plurality of sections with different aperture patterns arranged in the sections.
  • the section dimensions are smaller than, or preferably match the beam dimensions.
  • the aperture layout of each section is designed to crystallize a seed portion in the underlying substrate, and laterally grow the Si island patterns in the direction that matches the channel of the subsequently formed TFTs.
  • the relationship between the aperture layout and the poly-Si islands is dependent upon the degree of magnification in the projection optical system.
  • the degree of magnification matches the exposure apparatus photolithography process.
  • the degree of magnification degree is 1:1.
  • the mask sections are selected for lateral growth in a particular direction. That is, some mask sections have apertures for laterally growing a crystal structure in a first direction on the substrate, while other mask sections have apertures for laterally growing crystal is a second direction that is transverse (perpendicular) to the first direction.
  • FIGS. 3 a through 3 c are diagrams illustrating the use of different mask sections to promote lateral growth in transverse directions.
  • FIG. 3 a is a plan view of TFT with a first channel area 31 and a second channel area 32 .
  • FIG. 3 b is a plan view of a first mask pattern with a first aperture 33 .
  • Aperture pattern 33 is used to form the first channel area 31 of FIG. 3 a .
  • An initial shot through the aperture 33 produces a seed crystal area 34 on the silicon substrate.
  • the seed crystal is laterally grown.
  • the laterally grown crystals are represented by reference designator 36 .
  • FIG. 3 c illustrates the next step in the crystallization process.
  • a second mask section is used with an aperture pattern 37 , and the laser beam is rotated.
  • Aperture pattern 37 is used to for the channel region 32 of FIG. 3 a .
  • An initial shot through the aperture 37 produces a seed crystal area 38 on the silicon substrate.
  • the mask, and more specifically the aperture 37 is stepped across the substrate in the second direction 39 , the seed crystal is laterally grown 40 .
  • the first direction 35 is transverse to the second direction 39 .
  • Lateral growth areas 36 and 40 are subsequently formed into the channel regions 31 and 32 shown in FIG. 3 a .
  • alternate mask sections with different aperture patterns can be used to create additional channel region shapes on a substrate.
  • FIG. 4 is a plan view of the mask registration section 128 of FIG. 1.
  • FIG. 5 is cross-sectional view (a-b) of FIG. 4.
  • an alignment mark is projected on the Si precursor film at a predetermined location.
  • the aperture pattern shown in FIG. 4 is “cross-shaped”, but other patterns would also be practical. Irradiating a laser beam through the pattern leads to the ridge 53 of the Si film 52 that can be detected by a pattern recognition system installed in a photolithography exposure apparatus.
  • FIG. 6 is a plan view of a liquid crystal display substrate 61 with a plurality of panels, of which the first panel 62 is exemplary. Assuming that a panel corresponds to one shot of the exposure in a photolithography step, the panel layout would require at least one alignment mark, as described above.
  • FIG. 7 is a detailed depiction of the first panel 62 of FIG. 6. Alignment marks 76 and 77 are made as described above.
  • the areas of data line driver circuits 72 and 73 , and scan line driver circuits 74 are crystallized through three different corresponding sections of the shadow mask.
  • the pixel region 75 is crystallized as sub-areas (separated by dotted lines), where each sub-area is formed using the same shadow mask section. That is because each sub-area forms the same arrangement of TFTs. Alternately, some of the sub-areas can have different TFT layouts and, as a result, are formed using different shadow mask sections.
  • the silicon islands are defined through the conventional photolithography process steps, followed by the conventional process steps to complete TFT device.
  • the application of the present invention poly-Si process is not limited to liquid crystal displays. It can also be used to fabricate other products like sensors, data processors, and the like.
  • FIG. 8 is a flowchart illustrating the present invention multi-pattern shadow mask method for laser annealing. Although this method is depicted as a sequence of numbered steps for clarity, no order should be inferred from the numbering unless explicitly stated. It should be understood that some of these steps may be skipped, performed in parallel, or performed without the requirement of maintaining a strict order of sequence.
  • the methods start at Step 800 .
  • Step 802 supplies a silicon substrate.
  • Step 804 creates substrate alignment marks.
  • Step 806 with respect to the alignment marks, laser anneals a substrate region in a plurality of aperture patterns.
  • Step 808 forms a corresponding plurality of polycrystalline regions.
  • Step 810 forms a corresponding plurality of transistor channel regions in the plurality of polycrystalline regions. When the substrate is silicon, Step 810 forms polysilicon regions.
  • laser annealing a substrate region in a plurality of aperture patterns with respect to the alignment marks in Step 806 includes forming a rectangular substrate region with alignment marks in at least two substrate region corners.
  • laser annealing in a plurality of aperture patterns in Step 806 includes substeps.
  • laser annealing in a first substrate region with a first aperture pattern in Step 806 a includes substeps.
  • Step 806 a 1 laser anneals a first area of the first substrate region with the first aperture pattern.
  • Step 806 a 2 step-and-repeat laser anneals in a second area, adjacent the first area, in the substrate region.
  • the step-and-repeat annealing process includes the repetition of Step 806 b 2 many times.
  • forming a corresponding plurality of polycrystalline regions in Step 808 includes laterally growing crystals in response to the step-and-repeat laser annealing process. Other polycrystalline regions are formed through equivalent substeps.
  • Step 801 a supplies a multi-pattern shadow mask with a plurality of aperture patterns. Then, laser annealing in a plurality of aperture patterns in Step 806 includes using the shadow mask to create the plurality of aperture patterns.
  • the shadow mask includes a plurality of sections, each section having at least one aperture pattern. Then, using the shadow mask to create the plurality of aperture patterns in Step 806 includes selecting a shadow mask section to create a corresponding aperture pattern in the substrate.
  • supplying a shadow mask with a plurality of sections in Step 801 a includes supplying a shadow mask with a first section having a first aperture pattern and a second section having a second aperture pattern. Then, using the shadow mask to create the plurality of aperture patterns in Step 806 includes other substeps. For example, Step 806 a can laser anneal with a first aperture pattern in response to using the shadow mask first section. Likewise, Step 806 b can laser anneal with a second aperture pattern in response to using the shadow mask second section.
  • Step 801 a supplying a shadow mask with a plurality of sections in Step 801 a includes each shadow mask section having a plurality of aperture patterns.
  • Step 806 includes creating a plurality of aperture patterns in response to using each shadow mask section.
  • Using the shadow mask to create the plurality of aperture patterns can include other substeps.
  • Step 806 e selects a first mask section with a plurality of aperture patterns.
  • Step 806 f using the alignment marks, aligns a substrate region with the first mask. The alignment marks may have been formed earlier in the process.
  • Step 806 g uses the first mask section to step-and-repeat laser anneal regions in the substrate with the plurality of aperture patterns.
  • Step 806 h selects a second mask section with a plurality of aperture patterns.
  • Step 806 i uses the alignment marks, aligns a substrate region with the second mask.
  • Step 806 j uses the second mask section to step-and-repeat laser anneal regions in the substrate with the plurality of aperture patterns.
  • forming polycrystalline regions in a plurality of patterns in Step 808 includes substeps.
  • Step 808 a forms a plurality of polycrystalline patterns in response to laser annealing with the first mask section.
  • Step 808 b forms a plurality of polycrystalline patterns in response to laser annealing with the second mask section.
  • forming a corresponding plurality of transistor channel regions in Step 810 includes forming a liquid crystal display (LCD) panel with regions such as pixel regions, gate driver regions, source driver regions, digital-to-analog converter regions, analog amplifier regions, shift register regions, memory regions, and microprocessor regions.
  • LCD liquid crystal display
  • supplying a shadow mask with a plurality of sections in Step 801 a includes supplying a shadow mask with a first section having a first aperture pattern and a second section having a second aperture pattern. Then, using the shadow mask to create the plurality of aperture patterns in Step 806 includes other substeps. For example, Step 806 g may step-and-repeat laser anneal in a first direction on the substrate using the first aperture pattern of the shadow mask first section. Step 806 j may step-and-repeat laser anneal in a second direction, transverse to the first direction, on the substrate using a second aperture of the shadow mask second section.
  • the method further comprises a step, Step 801 b , of supplying a transverse orienting laser beam. Then, laser annealing in the first direction in Step 806 k includes orienting the laser beam in a first orientation. Laser annealing in the second direction in Step 806 l includes orienting the laser beam in a second orientation, transverse to the first orientation.
  • a system and method for laser annealing using a multi-section shadow mask have been provided. Examples have been provided for a shape and organization of the mask, but other possibilities are practical. Examples have also been given for the use and end-products resulting from the use of the mask, however, the present invention is not limited to just these examples. Other variations and embodiments will occur to those skilled in the art.

Abstract

A multi-pattern shadow mask, shadow mask laser annealing system, and a multi-pattern shadow mask method for laser annealing are provided. The method comprises: supplying a silicon substrate; supplying a multi-pattern shadow mask with a plurality of aperture patterns; creating substrate alignment marks; with respect to the alignment marks, laser annealing a substrate region in a plurality of aperture patterns; forming a corresponding plurality of polysilicon regions; and, forming a corresponding plurality of transistor channel regions in the plurality of polysilicon regions. In some aspects of the method laser annealing in a plurality of aperture patterns includes: laser annealing a first area in a substrate region with a first aperture pattern; and, stepping and repeating the laser annealing in a second area, adjacent the first area, in the substrate region. Then, forming a corresponding plurality of polycrystalline regions includes laterally growing crystals in response to the step-and-repeat laser annealing process. Typically, the shadow mask includes a plurality of sections, with each section having at least one aperture pattern. A shadow mask section can be selected to create a corresponding aperture pattern. If the mask section includes a plurality of aperture patterns, the selection of section creates all the corresponding aperture patterns in the selected section. More specifically, using the shadow mask to create the plurality of aperture patterns includes: selecting a first mask section with a plurality of aperture patterns; using the alignment marks, aligning the substrate with the first mask; using the first mask section to step-and repeat laser anneal regions in the substrate with the plurality of aperture patterns; selecting a second mask section with a plurality of aperture patterns; using the alignment marks, aligning the substrate with the second mask; using the second mask section to step-and repeat laser anneal regions in the substrate with the plurality of aperture patterns.

Description

    CROSS REFERENCE TO RELATED APPLICATION
  • This application is a divisional of application Ser. No. 10/124,853, filed Apr. 17, 2002, entitled “Multi-Pattern Shadow Mask System and Method for Laser Annealing,” invented by Adachi et al., now U.S. Pat. No. 6,727,125.[0001]
  • BACKGROUND OF THE INVENTION
  • 1. Field of the Invention [0002]
  • This invention generally relates to the fabrication of thin film transistors (TFTs) for liquid crystal displays (LCDs) and, more particularly, to a system and method for using a shadow mask for the laser annealing of silicon substrates, to form precisely located polysilicon or single crystal active regions. [0003]
  • 2. Description of the Related Art [0004]
  • The TFTs used in LCD active layer are made from either polycrystalline or single grain crystalline silicon (Si) films that are crystallized in response to laser annealing an amorphous silicon precursor film. These TFTs are used to form pixel switching devices, and/or LCD peripheral circuits, and/or electro-luminescence displays. They are also used in the fabrication of various integrated circuits like sensor arrays on a glass substrate. [0005]
  • A major industrial application of poly-Si thin film transistors (TFT) is LCD panels with driver circuit integration on the substrates. The quality of poly-Si (polycrystallized silicon) film that is the semiconductor layer of the transistors is one of the most important factors in the formation of TFTs, and directly affects the circuit performance. Poly-Si films typically consist of crystal grains and boundaries between the grains. The grains often include crystal defects. One approach for the improvement of the poly-Si film quality is in the use of a laser annealing method that can crystallize amorphous silicon precursor into a poly-Si film with fewer intra-grain defects. [0006]
  • High-performance TFTs require high electron mobility through the transistor channel region. One TFT fabrication problem is in the control of these channel locations on the substrate. That is, the channels must be located in predetermined substrate areas that are formed from either polycrystalline of single crystal material. Likewise, the orientation, or “direction” of the transistor channel is important when fitting the channel regions inside polycrystalline regions. [0007]
  • As a next generation laser annealing technology, a laser induced lateral growth crystallization technique is described in U.S. Pat. No. 6,322,625 (Im). This technology features the seed area of the film being localized by laser beam irradiation, defined through a patterned projection mask that is a shadow mask. Localized solidification occurs laterally from the seed area. By the use of this technique, the quality of the localized area in the poly-Si film is improved. Along the direction of lateral growth, the grain boundaries can be reduced dramatically. However, in the perpendicular direction the grain boundaries are likely to be degraded even further. Therefore, the best performing TFTs have channel regions are formed in the localized high quality poly-Si area, with channels formed in a direction parallel to the lateral growth. Using this process, a semiconductor material having regular, quasi-regular, or single-crystal structure can be made by a technique involving localized irradiation of the film with one or several pulses of a beam of laser radiation. A patterned projection mask defines the localized irradiation of the laser beam. The technique can be used in the manufacture of high-speed liquid crystal display devises, wherein pixel switches or/and driver circuitry are made in single-crystal or regular polycrystalline films. [0008]
  • A technique of locating transistor channels in a polycrystalline silicon film is disclosed in U.S. Pat. No. 6,281,470 (Adachi). The active layer of all the semiconductor elements are formed in alternating regions of silicon film having different crystallization characteristics. However, this process has profound limitations as an efficient fabrication procedure. [0009]
  • It would be advantageous if transistor channels could be defined more precisely in predetermined polycrystalline, or single crystal substrate regions. [0010]
  • It would be advantageous if a shadow mask laser annealing process could be used more for more precisely locating transistor channel regions. [0011]
  • SUMMARY OF THE INVENTION
  • The present invention laser annealing system and method features the use of a shadow mask for the patterned projection of a laser beam. The mask is divided into block patterns called sections. The mask has the capability of making alignment marks for the exposure equipment that permits precision alignment. The mask also permits multi-shot laser irradiation. Because of these features, the present invention laser annealing apparatus is able to supply higher performance TFTs and higher yields. The apparatus can control the location and direction of the localized high quality poly-Si area, to match to the layout design (formation) of the TFT channel regions. [0012]
  • The present invention shadow mask includes a plurality of sections with the different aperture patterns, corresponding the layout design of the poly-Si TFT channel regions. Some aperture patterns are designed to form a seed portion of the poly-Si material that is grown laterally by stepping the position of the laser beam, through the same aperture pattern, across the-substrate. Other aperture patterns form an alignment mark that is used by the exposure apparatus to precisely define the location of poly-Si islands and localized high quality poly-Si areas. The irradiation can be done with plurality of shots per at the same substrate position through an area of the patterned projection mask to avoid the defects of the poly-Si film caused by the fluctuation in the power of laser beam. [0013]
  • Accordingly, a multi-pattern shadow mask method is provided for laser annealing, the method comprises: supplying a silicon substrate; supplying a multi-pattern shadow mask with a plurality of aperture patterns; creating substrate alignment marks; with respect to the alignment marks, laser annealing a substrate region in a plurality of aperture patterns; forming a corresponding plurality of polysilicon regions; and, forming a corresponding plurality of transistor channel regions in the plurality of polysilicon regions. [0014]
  • In some aspects of the method, laser annealing in a plurality of aperture patterns includes: laser annealing a first area in a substrate region with a first aperture pattern; and, step-and-repeat laser annealing in a second area, adjacent the first area, in the substrate region. Then, forming a corresponding plurality of polycrystalline regions includes laterally growing crystals in response to the step-and-repeat laser annealing process. [0015]
  • Typically, the shadow mask includes a plurality of sections, with each section having at least one aperture pattern. A shadow mask section can be selected to create a corresponding aperture pattern. If the mask section includes a plurality of aperture patterns, the selection of mask section creates all the corresponding aperture patterns in the selected section. [0016]
  • More specifically, using the shadow mask to create the plurality of aperture patterns includes: selecting a first mask section with a plurality of aperture patterns; using the alignment marks, aligning the substrate with the first mask; using the first mask section to step-and repeat laser anneal regions in the substrate with the plurality of aperture patterns; selecting a second mask section with a plurality of aperture patterns; using the alignment marks, aligning the substrate with the second mask; using the second mask section to step-and repeat laser anneal regions in the substrate with the plurality of aperture patterns. Then, forming polycrystalline regions in a plurality of patterns includes: forming a plurality of polycrystalline patterns in response to laser annealing with the first mask section; and, forming a plurality of polycrystalline patterns in response to laser annealing with the second mask section. [0017]
  • Additional details of the above-described method, a multi- pattern shadow mask, and a multi-pattern shadow mask annealing system are described below. [0018]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIGS. 1[0019] a through 1 c are plan views of an exemplary present invention multi-pattern shadow mask.
  • FIG. 2 is a perspective view of the present invention multi-pattern shadow mask laser annealing system. [0020]
  • FIGS. 3[0021] a through 3 c are diagrams illustrating the use of different mask sections to promote lateral growth in transverse directions.
  • FIGS. 4 and 5 illustrate the mask registration section in detail and the resultant alignment mark formed in a substrate, in response to using the registration section. [0022]
  • FIG. 6 is a plan view of a liquid crystal display substrate with a plurality of panels, of which the first panel is exemplary. [0023]
  • FIG. 7 is a detailed depiction of the first panel of FIG. 6. [0024]
  • FIG. 8 is a flowchart illustrating the present invention multi-pattern shadow mask method for laser annealing.[0025]
  • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • FIGS. 1[0026] a through 1 c are plan views of an exemplary present invention multi-pattern shadow mask. As shown in FIG. 1a, the mask 100 comprises a plurality of shadow mask sections with apertures. Shown are sections 102, 104, 106, 108, 110, 112, 114, and 116. Each section includes at least one substrate alignment aperture. As seen in FIG. 1a, mask section 106 includes at least two aperture patterns. In FIG. 1b, aperture pattern 118 is shown in detail. Likewise, FIG. 1c shows aperture pattern 120 of mask section 108 is detail. Returning to FIG. 1a, it can be seen that the mask 100 includes a plurality of laser annealing aperture patterns and that each mask section includes at least one pattern of apertures. As in section 106 for example, each section often includes apertures in a plurality of patterns.
  • It is typical that each mask section is defined as a rectangle with a length and width. For example, [0027] mask section 114 is shown as having a length 122 and a width 124. However, the present invention mask sections are not limited to any particular shape. It is also typical to transversely locate the rectangular mask sections on the mask 100. For example, mask section 112 is transversely located, or perpendicular to mask section 114.
  • The [0028] shadow mask 100 includes at least one registration section with at least one substrate alignment aperture for forming a position reference mark on a substrate. The shadow mask 100 includes at least two corners, with a first registration section 126 formed in a first mask corner and a second registration section 128 formed in a second mask corner. The aperture pattern shown is a cross shape. However, the registration section need not be placed in the corners of the mask 100, and the aperture pattern need not necessarily be shaped as shown.
  • Returning to FIG. 1[0029] b, mask section 106 includes aperture pattern 118 formed as a rectangle with a first length 130 and first width 132. As seen in FIG. 1c, mask section 108 includes aperture pattern 120 formed as a rectangle with a second length 134 and a second width 136. Aperture pattern 120 can be considered to be transversely located with respect to the first aperture 118 (see FIG. 1b). That is, the length 134 is perpendicular to length 130.
  • FIG. 2 is a perspective view of the present invention multi-pattern shadow mask laser annealing system. The [0030] system 200 comprises a laser and associated optics system (not shown) to supply a laser beam that is represented by reference designator 202. Also shown is a shadow mask 100, as described in detail above. A lens 203 projects the laser beam after it passes through the mask apertures.
  • The laser supplies a [0031] beam 202 which can be defined as a rectangle with a length 204 and a width 206. The length 204 and width 206 of the beam match the length (122) and width (124) of the mask sections (see FIG. 1a). The beam dimensions need not necessarily match the mask section dimensions, but a close match promotes efficiency.
  • As shown with [0032] reference designator 208, the laser is capable of transverse movement to supply a beam in a first orientation (as shown) with respect to the shadow mask, and a second orientation (not shown), transverse to the first orientation. This transverse movement permits the laser beam 202 to be moved over transversely oriented mask sections. If the mask includes no transverse sections, the laser beam need not be capable of transverse movement.
  • Also shown is a [0033] silicon substrate 210 with a plurality of typically rectangular substrate regions. These regions are seen as panels in FIG. 6, described below. Alignment marks 212 and 214 are formed in at least two of the corners of each substrate region 216 (see FIG. 1a, reference designators 126 and 128). A plurality of polycrystalline patterns are formed in the substrate region 216 in response to laser annealing with one of the shadow mask sections. As described in more detail below, the substrate includes polycrystalline patterns laterally grown in a first direction in response to the first mask first aperture pattern and polycrystalline pattern laterally grown in a second direction, transverse to the first direction, in response to the second mask section second aperture pattern.
  • Functional Description
  • To fabricate an LCD using the above-described shadow mask annealing process, a Si precursor film, preferably amorphous Si film deposited by a plasma CVD (Chemical Vapor Deposition) having a thickness of 50 nanometers (nm), is formed over a protective layer (not shown) on a glass, quartz, or plastic substrate (not shown). The protective layer is typically a silicon oxide film having a thickness of 500 nm. [0034]
  • The laser beam irradiates a section of the shadow mask and the aperture pattern of the mask is projected through the lens on the Si precursor film. The laser beam can be generated by a XeCl excimer laser. As shown, the optical system has capability of rotating at least 90 degrees. The projection optical system is shown as a lens, but it can be an equivalent projection or a magnificent projection system. In the case of an equivalent projection system, the energy density of the laser may be great enough to damage to the shadow mask. Therefore, a durable mask material must be used, or a technique of beam splitting and re-synthesis before and after irradiation of the mask is required. [0035]
  • As shown in FIG. 1, the shadow mask has a plurality of sections with different aperture patterns arranged in the sections. The section dimensions are smaller than, or preferably match the beam dimensions. The aperture layout of each section is designed to crystallize a seed portion in the underlying substrate, and laterally grow the Si island patterns in the direction that matches the channel of the subsequently formed TFTs. The relationship between the aperture layout and the poly-Si islands is dependent upon the degree of magnification in the projection optical system. Preferably, the degree of magnification matches the exposure apparatus photolithography process. Preferably, the degree of magnification degree is 1:1. [0036]
  • The mask sections are selected for lateral growth in a particular direction. That is, some mask sections have apertures for laterally growing a crystal structure in a first direction on the substrate, while other mask sections have apertures for laterally growing crystal is a second direction that is transverse (perpendicular) to the first direction. [0037]
  • FIGS. 3[0038] a through 3 c are diagrams illustrating the use of different mask sections to promote lateral growth in transverse directions. FIG. 3a is a plan view of TFT with a first channel area 31 and a second channel area 32.
  • FIG. 3[0039] b is a plan view of a first mask pattern with a first aperture 33. Aperture pattern 33 is used to form the first channel area 31 of FIG. 3a. An initial shot through the aperture 33 produces a seed crystal area 34 on the silicon substrate. As the mask, and more specifically the aperture 33, is stepped across the substrate in the first direction 35, the seed crystal is laterally grown. The laterally grown crystals are represented by reference designator 36.
  • FIG. 3[0040] c illustrates the next step in the crystallization process. After area 36 is formed, a second mask section is used with an aperture pattern 37, and the laser beam is rotated. Aperture pattern 37 is used to for the channel region 32 of FIG. 3a. An initial shot through the aperture 37 produces a seed crystal area 38 on the silicon substrate. As the mask, and more specifically the aperture 37, is stepped across the substrate in the second direction 39, the seed crystal is laterally grown 40. Note that the first direction 35 is transverse to the second direction 39. Lateral growth areas 36 and 40 are subsequently formed into the channel regions 31 and 32 shown in FIG. 3a. In a similar manner, alternate mask sections with different aperture patterns can be used to create additional channel region shapes on a substrate.
  • FIGS. 4 and 5 illustrate the mask registration section in detail and the resultant alignment mark formed in a substrate, in response to using the registration section. FIG. 4 is a plan view of the [0041] mask registration section 128 of FIG. 1. FIG. 5 is cross-sectional view (a-b) of FIG. 4. Before the crystallization procedure, an alignment mark is projected on the Si precursor film at a predetermined location. The aperture pattern shown in FIG. 4 is “cross-shaped”, but other patterns would also be practical. Irradiating a laser beam through the pattern leads to the ridge 53 of the Si film 52 that can be detected by a pattern recognition system installed in a photolithography exposure apparatus.
  • FIG. 6 is a plan view of a liquid [0042] crystal display substrate 61 with a plurality of panels, of which the first panel 62 is exemplary. Assuming that a panel corresponds to one shot of the exposure in a photolithography step, the panel layout would require at least one alignment mark, as described above.
  • FIG. 7 is a detailed depiction of the [0043] first panel 62 of FIG. 6. Alignment marks 76 and 77 are made as described above. The areas of data line driver circuits 72 and 73, and scan line driver circuits 74 are crystallized through three different corresponding sections of the shadow mask. The pixel region 75 is crystallized as sub-areas (separated by dotted lines), where each sub-area is formed using the same shadow mask section. That is because each sub-area forms the same arrangement of TFTs. Alternately, some of the sub-areas can have different TFT layouts and, as a result, are formed using different shadow mask sections.
  • After the crystallization process, the silicon islands are defined through the conventional photolithography process steps, followed by the conventional process steps to complete TFT device. The application of the present invention poly-Si process is not limited to liquid crystal displays. It can also be used to fabricate other products like sensors, data processors, and the like. [0044]
  • FIG. 8 is a flowchart illustrating the present invention multi-pattern shadow mask method for laser annealing. Although this method is depicted as a sequence of numbered steps for clarity, no order should be inferred from the numbering unless explicitly stated. It should be understood that some of these steps may be skipped, performed in parallel, or performed without the requirement of maintaining a strict order of sequence. The methods start at [0045] Step 800. Step 802 supplies a silicon substrate. Step 804 creates substrate alignment marks. Step 806, with respect to the alignment marks, laser anneals a substrate region in a plurality of aperture patterns. Step 808 forms a corresponding plurality of polycrystalline regions. Step 810 forms a corresponding plurality of transistor channel regions in the plurality of polycrystalline regions. When the substrate is silicon, Step 810 forms polysilicon regions.
  • In some aspects of the method, laser annealing a substrate region in a plurality of aperture patterns with respect to the alignment marks in [0046] Step 806 includes forming a rectangular substrate region with alignment marks in at least two substrate region corners.
  • In other aspects, laser annealing in a plurality of aperture patterns in [0047] Step 806 includes substeps. Step 806 a laser anneals a first substrate region with a first pattern. Step 806 b laser anneals a second substrate region with a second pattern.
  • In some aspects, laser annealing in a first substrate region with a first aperture pattern in [0048] Step 806 a includes substeps. Step 806 a 1 laser anneals a first area of the first substrate region with the first aperture pattern. Step 806 a 2 step-and-repeat laser anneals in a second area, adjacent the first area, in the substrate region. Typically, the step-and-repeat annealing process includes the repetition of Step 806 b 2 many times. Then, forming a corresponding plurality of polycrystalline regions in Step 808 includes laterally growing crystals in response to the step-and-repeat laser annealing process. Other polycrystalline regions are formed through equivalent substeps.
  • In some aspects, Step [0049] 801 a supplies a multi-pattern shadow mask with a plurality of aperture patterns. Then, laser annealing in a plurality of aperture patterns in Step 806 includes using the shadow mask to create the plurality of aperture patterns. Typically, the shadow mask includes a plurality of sections, each section having at least one aperture pattern. Then, using the shadow mask to create the plurality of aperture patterns in Step 806 includes selecting a shadow mask section to create a corresponding aperture pattern in the substrate.
  • In some aspects, supplying a shadow mask with a plurality of sections in [0050] Step 801 a includes supplying a shadow mask with a first section having a first aperture pattern and a second section having a second aperture pattern. Then, using the shadow mask to create the plurality of aperture patterns in Step 806 includes other substeps. For example, Step 806 a can laser anneal with a first aperture pattern in response to using the shadow mask first section. Likewise, Step 806 b can laser anneal with a second aperture pattern in response to using the shadow mask second section.
  • In other aspects, supplying a shadow mask with a plurality of sections in [0051] Step 801 a includes each shadow mask section having a plurality of aperture patterns. Then, Step 806 includes creating a plurality of aperture patterns in response to using each shadow mask section. Using the shadow mask to create the plurality of aperture patterns can include other substeps. Step 806 e selects a first mask section with a plurality of aperture patterns. Step 806 f, using the alignment marks, aligns a substrate region with the first mask. The alignment marks may have been formed earlier in the process. Step 806 g uses the first mask section to step-and-repeat laser anneal regions in the substrate with the plurality of aperture patterns. Step 806 h selects a second mask section with a plurality of aperture patterns. Step 806 i using the alignment marks, aligns a substrate region with the second mask. Step 806 j uses the second mask section to step-and-repeat laser anneal regions in the substrate with the plurality of aperture patterns. Then, forming polycrystalline regions in a plurality of patterns in Step 808 includes substeps. Step 808 a forms a plurality of polycrystalline patterns in response to laser annealing with the first mask section. Step 808 b forms a plurality of polycrystalline patterns in response to laser annealing with the second mask section.
  • In some aspects, forming a corresponding plurality of transistor channel regions in [0052] Step 810 includes forming a liquid crystal display (LCD) panel with regions such as pixel regions, gate driver regions, source driver regions, digital-to-analog converter regions, analog amplifier regions, shift register regions, memory regions, and microprocessor regions.
  • In other aspects of the method, supplying a shadow mask with a plurality of sections in [0053] Step 801 a includes supplying a shadow mask with a first section having a first aperture pattern and a second section having a second aperture pattern. Then, using the shadow mask to create the plurality of aperture patterns in Step 806 includes other substeps. For example, Step 806 g may step-and-repeat laser anneal in a first direction on the substrate using the first aperture pattern of the shadow mask first section. Step 806 j may step-and-repeat laser anneal in a second direction, transverse to the first direction, on the substrate using a second aperture of the shadow mask second section.
  • Some aspects the method further comprises a step, [0054] Step 801 b, of supplying a transverse orienting laser beam. Then, laser annealing in the first direction in Step 806 k includes orienting the laser beam in a first orientation. Laser annealing in the second direction in Step 806 l includes orienting the laser beam in a second orientation, transverse to the first orientation.
  • A system and method for laser annealing using a multi-section shadow mask have been provided. Examples have been provided for a shape and organization of the mask, but other possibilities are practical. Examples have also been given for the use and end-products resulting from the use of the mask, however, the present invention is not limited to just these examples. Other variations and embodiments will occur to those skilled in the art.[0055]

Claims (30)

We claim:
1. A multi-pattern shadow mask method for laser annealing, the method comprising:
creating substrate alignment marks;
with respect to the alignment marks, laser annealing a substrate region in a plurality of aperture patterns; and,
forming a corresponding plurality of polycrystalline regions.
2. The method of claim 1 further comprising:
forming a corresponding plurality of transistor channel regions in the plurality of polycrystalline regions.
3. The method of claim 1 further comprising:
supplying a silicon substrate; and,
wherein forming a corresponding plurality of polycrystalline regions includes forming polysilicon regions.
4. The method of claim 3 wherein laser annealing a substrate region in a plurality of aperture patterns with respect to the alignment marks includes forming a rectangular substrate region with alignment marks in at least two substrate region corners.
5. The method of claim 4 wherein laser annealing in a plurality of aperture patterns includes:
laser annealing a first substrate region with a first aperture pattern; and,
laser annealing a second substrate region with a second aperture pattern.
6. The method of claim 5 wherein laser annealing in a first substrate region with a first aperture pattern includes:
laser annealing a first area of the first substrate region with the first aperture pattern;
step-and-repeat laser annealing in a second area, adjacent the first area, in the substrate region; and,
wherein forming a corresponding plurality of polycrystalline regions includes laterally growing crystals in response to the step-and-repeat laser annealing process.
7. The method of claim 6 further comprising:
supplying a multi-pattern shadow mask with a plurality of aperture patterns; and,
wherein laser annealing in a plurality of aperture patterns includes using the shadow mask to create the plurality of aperture patterns.
8. The method of claim 7 wherein supplying a multi-pattern shadow mask with a plurality of aperture patterns includes supplying a shadow mask with a plurality of sections, each section having at least one aperture pattern; and,
wherein using the shadow mask to create the plurality of aperture patterns includes selecting a shadow mask section to create a corresponding aperture pattern in the substrate.
9. The method of claim 8 wherein supplying a shadow mask with a plurality of sections, each section having at least one aperture pattern, includes supplying a shadow mask with a first section having a first aperture pattern and a second section having a second aperture pattern; and,
wherein using the shadow mask to create the plurality of aperture patterns includes:
laser annealing with a first aperture pattern in response to using the shadow mask first section; and,
laser annealing with a second aperture pattern in response to using the shadow mask second section.
10. The method of claim 9 wherein supplying a shadow mask with a plurality of sections, each section having at least one aperture pattern, includes each shadow mask section having a plurality of aperture patterns; and,
wherein using the shadow mask to create the plurality of aperture patterns includes creating a plurality of aperture patterns in response to using each shadow mask section.
11. The method of claim 10 wherein using the shadow mask to create the plurality of aperture patterns includes:
selecting a first mask section with a plurality of aperture patterns;
using the alignment marks, aligning a substrate region with the first mask;
using the first mask section to step-and-repeat laser anneal regions in the substrate with the plurality of aperture patterns;
selecting a second mask section with a plurality of aperture patterns;
using the alignment marks, aligning a substrate region with the second mask;
using the second mask section to step-and repeat laser anneal regions in the substrate with the plurality of aperture patterns; and,
wherein forming polycrystalline regions in a plurality of patterns includes:
forming a plurality of polycrystalline patterns in response to laser annealing with the first mask section; and,
forming a plurality of polycrystalline patterns in response to laser annealing with the second mask section.
13. The method of claim 12 wherein forming a corresponding plurality of transistor channel regions in the plurality of polycrystalline regions includes forming a liquid crystal display (LCD) panel with regions selected from the group including pixel regions, gate driver regions, source driver regions, digital-to-analog converter regions, analog amplifier regions, shift register regions, memory regions, and microprocessor regions.
14. The method of claim 8 wherein supplying a shadow mask with a plurality of sections, each section having at least one aperture pattern, includes supplying a shadow mask with a first section having a first aperture pattern and a second section having a second aperture pattern; and,
wherein using the shadow mask to create the plurality of aperture patterns includes:
step-and-repeat laser annealing in a first direction on the substrate using the first aperture pattern of the shadow mask first section; and,
step-and-repeat laser annealing in a second direction, transverse to the first direction, on the substrate using a second aperture of the shadow mask second section.
15. The method of claim 14 further comprising:
supplying a transverse orienting laser beam;
wherein laser annealing in the first direction includes orienting the laser beam in a first orientation; and,
wherein laser annealing in the second direction includes orienting the laser beam in a second orientation, transverse to the first orientation.
16. A multi-pattern shadow mask comprising:
a plurality of shadow mask sections;
at least one substrate alignment aperture;
a plurality of laser annealing aperture patterns; and,
wherein each mask section includes at least one pattern of apertures.
17. The shadow mask of claim 16 wherein each section includes apertures in a plurality of patterns.
18. The shadow mask of claim 15 wherein each section is defined as a rectangle with a length and a width.
19. The shadow mask of claim 18 wherein the plurality of shadow mask sections include a first section and a second section, transversely located with respect to the first section.
20. The shadow mask of claim 18 wherein the mask includes at least one registration section with at least one substrate alignment aperture for forming a position reference mark on a substrate.
21. The shadow mask of claim 20 in which the mask includes at least two corners;
wherein a first registration section is formed in a first mask corner; and,
wherein a second registration section is formed in a second mask corner.
22. The shadow mask of claim 17 wherein a first mask section includes a first aperture pattern formed as a rectangle with a first length and first width; and,
wherein a second mask section includes a second aperture pattern formed as a rectangle with a second length and a second width, transversely located with respect to the first aperture.
23. A multi-pattern shadow mask laser annealing system, the system comprising:
a laser to supply a laser beam; and,
a shadow mask including:
a plurality of shadow mask sections;
at least one substrate alignment aperture;
a plurality of laser annealing aperture patterns; and,
wherein each mask section includes at least one pattern of apertures.
24. The laser annealing system of claim 23 wherein each shadow mask section includes apertures in a plurality of patterns.
25. The laser annealing system of claim 23 wherein the laser supplies a beam defined as a rectangle with a length and a width; and,
wherein each mask section is defined as a rectangle with the length the width.
26. The laser annealing system of claim 25 wherein the laser is capable of transverse movement to supply a beam in a first orientation with respect to the shadow mask and a second orientation, transverse to the first orientation; and,
wherein the plurality of mask sections include a first section and a second section, transversely located with respect to the first section.
27. The laser annealing system of claim 25 wherein the mask includes at least one registration section with at least one substrate alignment aperture for forming a position reference mark on a substrate.
28. The laser annealing system of claim 27 wherein the mask includes at least two corners;
wherein the mask includes a first registration section formed in a first mask corner, and a second registration section formed in a second mask corner.
29. The laser annealing system of claim 28 further comprising:
a silicon substrate including a plurality of rectangular substrate regions, each substrate region having alignment marks formed in at least two of corners in response to the mask registration sections, and a plurality of polycrystalline patterns formed in response to laser annealing with a shadow mask section.
30. The laser annealing system of claim 29 wherein a first mask section includes a first aperture pattern formed as a rectangle with a first length and first width; and,
wherein a second mask section includes a second aperture pattern formed as a rectangle with a second length and a second width, transversely located with respect to the first aperture.
31. The laser annealing system of claim 30 wherein the substrate includes a first polycrystalline pattern laterally grown in a first direction in response to the first mask first aperture pattern and a second polycrystalline pattern laterally grown in a second direction, transverse to the first direction, in response to the second mask section second aperture pattern.
US10/831,443 2002-04-17 2004-04-23 Multi-pattern shadow mask system for laser annealing Abandoned US20040197972A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/831,443 US20040197972A1 (en) 2002-04-17 2004-04-23 Multi-pattern shadow mask system for laser annealing

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/124,853 US6727125B2 (en) 2002-04-17 2002-04-17 Multi-pattern shadow mask system and method for laser annealing
US10/831,443 US20040197972A1 (en) 2002-04-17 2004-04-23 Multi-pattern shadow mask system for laser annealing

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10/124,853 Division US6727125B2 (en) 2002-04-17 2002-04-17 Multi-pattern shadow mask system and method for laser annealing

Publications (1)

Publication Number Publication Date
US20040197972A1 true US20040197972A1 (en) 2004-10-07

Family

ID=29214662

Family Applications (3)

Application Number Title Priority Date Filing Date
US10/124,853 Expired - Lifetime US6727125B2 (en) 2002-04-17 2002-04-17 Multi-pattern shadow mask system and method for laser annealing
US10/831,671 Abandoned US20040224447A1 (en) 2002-04-17 2004-04-23 Multi-pattern shadow mask laser annealing system
US10/831,443 Abandoned US20040197972A1 (en) 2002-04-17 2004-04-23 Multi-pattern shadow mask system for laser annealing

Family Applications Before (2)

Application Number Title Priority Date Filing Date
US10/124,853 Expired - Lifetime US6727125B2 (en) 2002-04-17 2002-04-17 Multi-pattern shadow mask system and method for laser annealing
US10/831,671 Abandoned US20040224447A1 (en) 2002-04-17 2004-04-23 Multi-pattern shadow mask laser annealing system

Country Status (2)

Country Link
US (3) US6727125B2 (en)
JP (1) JP2003318111A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050250228A1 (en) * 2004-05-06 2005-11-10 Chung-Wen Ko Divided shadow mask for fabricating organic light emitting diode displays
US20070155102A1 (en) * 2005-12-29 2007-07-05 Infineon Technologies Ag Method of fabricating an integrated circuit
US20100026669A1 (en) * 2008-08-01 2010-02-04 Samsung Electronics Co., Ltd. Gate driving circuit, display device having the same, and method for manufacturing the display device
CN106098599A (en) * 2016-08-17 2016-11-09 京东方科技集团股份有限公司 A kind of laser anneal device and control method thereof

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SG120880A1 (en) * 2001-08-31 2006-04-26 Semiconductor Energy Lab Laser irradiation method, laser irradiation apparatus, and method of manufacturing a semiconductor device
TWI291729B (en) * 2001-11-22 2007-12-21 Semiconductor Energy Lab A semiconductor fabricating apparatus
US7133737B2 (en) 2001-11-30 2006-11-07 Semiconductor Energy Laboratory Co., Ltd. Program for controlling laser apparatus and recording medium for recording program for controlling laser apparatus and capable of being read out by computer
US6979605B2 (en) * 2001-11-30 2005-12-27 Semiconductor Energy Laboratory Co., Ltd. Manufacturing method for a semiconductor device using a marker on an amorphous semiconductor film to selectively crystallize a region with a laser light
US7214573B2 (en) * 2001-12-11 2007-05-08 Semiconductor Energy Laboratory Co., Ltd. Method of manufacturing a semiconductor device that includes patterning sub-islands
KR100484399B1 (en) * 2002-05-23 2005-04-20 엘지.필립스 엘시디 주식회사 mask for silicon crystallization and silicon crystallization method
US7387922B2 (en) * 2003-01-21 2008-06-17 Semiconductor Energy Laboratory Co., Ltd. Laser irradiation method, method for manufacturing semiconductor device, and laser irradiation system
KR100519948B1 (en) * 2003-05-20 2005-10-10 엘지.필립스 엘시디 주식회사 crystallization process of amorphous silicon and switching device using the same
KR100525443B1 (en) * 2003-12-24 2005-11-02 엘지.필립스 엘시디 주식회사 Device for Crystallization and method for Crystallization with the same
US7804148B2 (en) 2006-02-16 2010-09-28 International Business Machines Corporation Opto-thermal mask including aligned thermal dissipative layer, reflective layer and transparent capping layer
US9372241B2 (en) * 2009-11-06 2016-06-21 Headway Technologies, Inc. Multi-directional pin anneal of MR sensors with plasmon heating
EP2364809A1 (en) 2010-02-26 2011-09-14 Excico France Method and apparatus for irradiating a semiconductor material surface by laser energy
US8785815B2 (en) * 2012-06-22 2014-07-22 Applied Materials, Inc. Aperture control of thermal processing radiation
US9360284B1 (en) 2013-03-15 2016-06-07 Vista Outdoor Operations Llc Manufacturing process to produce metalurgically programmed terminal performance projectiles
AT517572B1 (en) * 2014-05-19 2018-11-15 Trotec Laser Gmbh Method for processing workpieces
CN109075043A (en) * 2016-03-04 2018-12-21 堺显示器制品株式会社 Laser anneal device, exposure mask, thin film transistor (TFT) and laser anneal method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5280215A (en) * 1990-11-22 1994-01-18 Kabushiki Kaisha Toshiba Shadow mask for color cathode ray tube
US6249335B1 (en) * 1992-01-17 2001-06-19 Nikon Corporation Photo-mask and method of exposing and projection-exposing apparatus
US6274198B1 (en) * 1997-02-24 2001-08-14 Agere Systems Optoelectronics Guardian Corp. Shadow mask deposition
US6281470B1 (en) * 1997-04-02 2001-08-28 Sharp Kabushiki Kaisha Thin film semiconductor device uniforming characteristics of semiconductor elements and manufacturing method thereof
US20020062785A1 (en) * 2000-11-28 2002-05-30 Lg Electronics Inc. Mask for fabricating display panel
US6589382B2 (en) * 2001-11-26 2003-07-08 Eastman Kodak Company Aligning mask segments to provide a stitched mask for producing OLED devices
US6897164B2 (en) * 2002-02-14 2005-05-24 3M Innovative Properties Company Aperture masks for circuit fabrication

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4667109A (en) * 1984-03-09 1987-05-19 Canon Kabushiki Kaisha Alignment device
US5083466A (en) * 1988-07-14 1992-01-28 University Of Hawaii Multidimensional force sensor
EP0355496A3 (en) * 1988-08-15 1990-10-10 Sumitomo Heavy Industries Co., Ltd. Position detector employing a sector fresnel zone plate
JP3033135B2 (en) * 1990-06-13 2000-04-17 株式会社ニコン Projection exposure apparatus and method
US5147826A (en) * 1990-08-06 1992-09-15 The Pennsylvania Research Corporation Low temperature crystallization and pattering of amorphous silicon films
US5145432A (en) * 1991-11-27 1992-09-08 Zenith Electronics Corporation Optical interprogation system for use in constructing flat tension shadow mask CRTS
JP3204986B2 (en) 1996-05-28 2001-09-04 ザ トラスティース オブ コロンビア ユニヴァーシティ イン ザ シティ オブ ニューヨーク Crystallization of semiconductor film region on substrate and device manufactured by this method
US6261406B1 (en) * 1999-01-11 2001-07-17 Lsi Logic Corporation Confinement device for use in dry etching of substrate surface and method of dry etching a wafer surface
JP2001023918A (en) * 1999-07-08 2001-01-26 Nec Corp Semiconductor thin-film forming apparatus
JP3393469B2 (en) * 1999-07-15 2003-04-07 日本電気株式会社 Thin film semiconductor device manufacturing method and thin film semiconductor forming apparatus
JP3751772B2 (en) * 1999-08-16 2006-03-01 日本電気株式会社 Semiconductor thin film manufacturing equipment
JP4322373B2 (en) * 1999-11-15 2009-08-26 日本電気株式会社 Film body part reforming apparatus and film body part reforming method
JP2001148480A (en) * 1999-11-18 2001-05-29 Nec Corp Thin film transistor and device and method for manufacturing the same
KR20020015028A (en) * 2000-02-08 2002-02-27 모리시타 요이찌 Lamp anneal device and substrate of display device
JP2002057105A (en) * 2000-08-14 2002-02-22 Nec Corp Method and device for manufacturing semiconductor thin film, and matrix circuit-driving device
US6849825B2 (en) * 2001-11-30 2005-02-01 Semiconductor Energy Laboratory Co., Ltd. Laser irradiation apparatus

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5280215A (en) * 1990-11-22 1994-01-18 Kabushiki Kaisha Toshiba Shadow mask for color cathode ray tube
US6249335B1 (en) * 1992-01-17 2001-06-19 Nikon Corporation Photo-mask and method of exposing and projection-exposing apparatus
US6274198B1 (en) * 1997-02-24 2001-08-14 Agere Systems Optoelectronics Guardian Corp. Shadow mask deposition
US6281470B1 (en) * 1997-04-02 2001-08-28 Sharp Kabushiki Kaisha Thin film semiconductor device uniforming characteristics of semiconductor elements and manufacturing method thereof
US20020062785A1 (en) * 2000-11-28 2002-05-30 Lg Electronics Inc. Mask for fabricating display panel
US6589382B2 (en) * 2001-11-26 2003-07-08 Eastman Kodak Company Aligning mask segments to provide a stitched mask for producing OLED devices
US6897164B2 (en) * 2002-02-14 2005-05-24 3M Innovative Properties Company Aperture masks for circuit fabrication

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050250228A1 (en) * 2004-05-06 2005-11-10 Chung-Wen Ko Divided shadow mask for fabricating organic light emitting diode displays
US7253533B2 (en) * 2004-05-06 2007-08-07 Au Optronics Corporation Divided shadow mask for fabricating organic light emitting diode displays
US20070155102A1 (en) * 2005-12-29 2007-07-05 Infineon Technologies Ag Method of fabricating an integrated circuit
US7622374B2 (en) 2005-12-29 2009-11-24 Infineon Technologies Ag Method of fabricating an integrated circuit
US20100026669A1 (en) * 2008-08-01 2010-02-04 Samsung Electronics Co., Ltd. Gate driving circuit, display device having the same, and method for manufacturing the display device
US8310432B2 (en) * 2008-08-01 2012-11-13 Samsung Electronics Co., Ltd. Gate driving circuit, display device having the same, and method for manufacturing the display device
CN106098599A (en) * 2016-08-17 2016-11-09 京东方科技集团股份有限公司 A kind of laser anneal device and control method thereof

Also Published As

Publication number Publication date
JP2003318111A (en) 2003-11-07
US20040224447A1 (en) 2004-11-11
US6727125B2 (en) 2004-04-27
US20030199176A1 (en) 2003-10-23

Similar Documents

Publication Publication Date Title
US6727125B2 (en) Multi-pattern shadow mask system and method for laser annealing
US6590228B2 (en) LCD device with optimized channel characteristics
US6573163B2 (en) Method of optimizing channel characteristics using multiple masks to form laterally crystallized ELA poly-Si films
US6755909B2 (en) Method of crystallizing amorphous silicon using a mask
KR100618184B1 (en) Method of crystallization
US6117752A (en) Method of manufacturing polycrystalline semiconductor thin film
US7078649B2 (en) Method of forming semiconductor thin-film and laser apparatus used therefore
US7033434B2 (en) Mask for crystallizing, method of crystallizing amorphous silicon and method of manufacturing array substrate using the same
KR20030030840A (en) Thin-film transistor device, its manufacturing process, and image display using the device
US7256109B2 (en) Isotropic polycrystalline silicon
US7205215B2 (en) Fabrication method of thin film transistor
US20020102821A1 (en) Mask pattern design to improve quality uniformity in lateral laser crystallized poly-Si films
US6660576B2 (en) Substrate and method for producing variable quality substrate material
EP0646950A2 (en) Method for processing a thin film
US7008863B2 (en) Method for forming polycrystalline silicon film
US7033915B2 (en) Method for crystallizing amorphous silicon film
EP1860699A1 (en) Display having thin fim transistors with channel region of varying crystal state
US20040258930A1 (en) Grain-free polycrystalline silicon and a method for producing same
JP2000349036A (en) Semiconductor treatment method and manufacture of semiconductor device
JP2008098310A (en) Crystallization method, crystallized substrate, manufacturing method of thin film transistor, thin film transistor, and display unit

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION