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Publication numberUS20010029158 A1
Publication typeApplication
Application numberUS 09/770,743
Publication dateOct 11, 2001
Filing dateJan 26, 2001
Priority dateJul 30, 1998
Publication number09770743, 770743, US 2001/0029158 A1, US 2001/029158 A1, US 20010029158 A1, US 20010029158A1, US 2001029158 A1, US 2001029158A1, US-A1-20010029158, US-A1-2001029158, US2001/0029158A1, US2001/029158A1, US20010029158 A1, US20010029158A1, US2001029158 A1, US2001029158A1
InventorsYoshitaka Sasaki, Atsushi Iijima, Toshio Kubota, Takehiro Horinaka
Original AssigneeYoshitaka Sasaki, Atsushi Iijima, Toshio Kubota, Takehiro Horinaka
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Polishing apparatus and polishing method, and method of manufacturing semiconductor device and method of manufacturing thin film magnetic head
US 20010029158 A1
Abstract
A polishing apparatus comprises a plurality of (three, for example) polishing portions and a cleaning portion. First, roughing is performed in a first polishing portion by a platen made of a hard grinder. The polishing surface of the platen is hard so that the wafer on the polishing surface exhibits no pattern dependence. Next, scratches and polishing distortion slightly generated on the wafer in the platen are removed (medium polishing) by a hard abrasive pad with a single-layered structure in a second polishing portion. Further, finishing is performed in a third polishing portion by an abrasive pad with a two-layered structure. At last, the contamination left by the micro scratches or slurry generated in the prior process is completely cleaned by a cleaning pad in the cleaning portion.
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Claims(9)
What is claimed is:
1. A polishing apparatus for polishing and planarizing a subject of polishing with a base having at least one layer, comprising:
a pedestal; and
a plurality of polishing portions each having a rotatable platen, provided on the pedestal and being moveable relative to the pedestal, for performing polishing of different degrees on at least one layer of the one subject of polishing, wherein
the rotatable platen of the plurality of polishing portions is formed with a resin defined by a base having a thickness with essentially no distortion.
2. The polishing apparatus according to
claim 1
, wherein the rotatable platen has a thickness of about 0.5 to about 5.0 mm.
3. The polishing apparatus according to
claim 2
, wherein the rotatable platen has a ring shape and a thickness of about 1.0 mm or less.
4. The polishing apparatus according to
claim 2
, wherein the rotatable platen has a ring shape.
5. The polishing apparatus according to
claim 1
, wherein the resin includes diamond grains.
6. The polishing apparatus according to
claim 1
, wherein the resin is comprised of at least one of a phenolic resin and an epoxy resin.
7. The polishing apparatus according to
claim 1
, wherein the resin is a glass resin.
8. The polishing apparatus according to
claim 1
, wherein the resin is polyurethane foam.
9. The polishing apparatus according to
claim 1
, wherein the rotatable platen has a ring shape and a thickness of about 1.0 mm or less.
Description
CROSS REFERENCE TO RELATED APPLICATION

[0001] This is a Continuation-in-Part of Application Ser. No. 09/359,807, filed Jul. 26, 1999. The entire disclosure of the prior application is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of Invention

[0003] The invention relates to a polishing apparatus and a polishing method for planarization of a thin film magnetic head, a semiconductor integrated circuit and so on, and a method of manufacturing a semiconductor device and a method of manufacturing a thin film magnetic head.

[0004] 2. Description of Related Art

[0005] In a manufacturing process of a semiconductor integrated circuit using silicon or the like, microfabrication of the metallic wiring is required in order to scale down a device and to improve performance of elements. Specifically, it is necessary to form the pattern with a submicron thickness and to laminate such patterns to form a multi-layer.

[0006] In such a multi level interconnect structure, interlayer insulating films made of silicon oxide film or other films are provided between each two metallic wiring layers. In the structure, the interlayer insulating films have steps about 0.5 to 0.7 μm deep because of the metallic wiring. Accordingly, it is necessary to planarize an interlayer insulating film before forming another metallic wiring thereon.

[0007] There is a similar problem in a manufacturing process of a thin film magnetic head. In recent years, performance improvement in thin film magnetic heads has been sought in accordance with improvement in surface recording density of a hard disk drive. A composite thin film magnetic head comprising a recording head with an inductive-type magnetic transducer and a reproducing head with a magnetoresistive element is widely used as a thin film magnetic head. There are several types of magnetoresistive elements: one is an AMR element using Anisotropic Magneto Resistive effect and another is a GMR element using Giant Magneto Resistive effect.

[0008] In such a composite thin film magnetic head, it is necessary to improve the performance both of the recording head and of the reproducing head. This has been achieved by microfabrication of tracks in addition to selecting materials suitable for each part of the composite thin film magnetic head.

[0009] Specifically, in order to increase the recording density of the recording head, microfabrication of the magnetic pole portion is required. Therefore, submicron processing using a semiconductor processing technique is applied. On the other hand, in order to write information accurately with the continued advance of microfabrication, it is necessary for at least one of the magnetic pole to be about 2.5 to 3.5 μm thick. Planarizarion of the underlying layer has been required for forming such a magnetic pole.

[0010] Similarly, in the reproducing head, it is necessary to form tracks with submicron widths in a magnetoresistive film. Usually, the magnetoresistive film is formed on a thick shield magnetic film with a thickness of about 2.0 to 3.0 μm with a shield gap layer in between. Accordingly, planarization of the underlying layer has been also required for forming a magnetoresistive film.

[0011] The performance of the recording head also depends on the distance from an air bearing surface (ABS), that is, a throat height. The throat height is determined by the amount of polishing at the time of processing the ABS. Further, the performance of the reproducing head also depends on the distance from the ABS, that is, an MR height. The MR height is also determined by the amount of polishing at the time of processing the ABS.

[0012] As described, the microfabrication technology and the planarization method have become the most important process techniques in accordance with the performance improvement in the semiconductor integrated circuit and the thin film magnetic head. The process of planarization is precisely performed provided the microfabrication process is accurately performed. Therefore, it is necessary to perform the planarization process accurately in order to improve the performance of the semiconductor device or the thin film head device.

[0013] Examples of planarization methods are CMP (Chemical Mechanical Polishing) using slurry (abrasives) and MP (Mechanical Polishing) for polishing by a platen in which fine diamond grains are scatteringly buried using oil or the like as lubricant.

[0014] CMP, however, has several problems since it has a polishing characteristic that the abrasive pad follows the wafer pattern. On the other hand, MP has a problem that scratches are easily formed on the surface of the wafer. In order to suppress the scratches, diamond grains with smaller diameters may be used. However, this may cause another problem that the polishing speed decreases.

[0015] The polishing apparatus using these methods has one platen and polishes the surface of the wafer. However, some apparatuses have two platens (AVANTE472; product of IPEC PLANER, for example). This type of polishing apparatus uses an abrasive pad with two-layered structure using relatively soft materials (IC1000, and suba 400 or 800; product of RODRAL Nitta, for example) for one of the platens, and a cleaning pad having a soft brush with long pile for the other platen. The apparatus removes the slurry attached by the cleaning pad after polishing once using the abrasive pad. Therefore, the apparatus also has several problems in controlling the amount of polishing because of the pattern dependence in the wafer, like the polishing apparatus with one platen.

[0016] In the followings, the specific problems when performing planarization using these polishing apparatuses will be described. First, the configurations of a semiconductor integrated circuit and a thin film magnetic head to which the planarization process is applied will be described.

[0017]FIG. 12 shows CMOS (Complementary Metal Oxide Semiconductor) circuit with a five level interconnect structure as an example of the semiconductor integrated circuit.

[0018] In the CMOS integrated circuit, an n-type well region 100 a is formed in a p-type substrate 100 made of such as silicon, for example. A LOCOS (Local Oxidation of Silicon) film 101 as an element isolation film is formed on the surface of a substrate 100. An n-type MOS transistor 107 comprises a pair of n-type impurity regions 103 and 104 as a source or a drain and a gate electrode 106 formed on the surface of the substrate 100 between the impurity regions 103 and 104 with a gate oxide film 105 in between. A p-type MOS transistor 107 a comprises p-type impurity regions 103 a and 104 a formed in the well region 100 a and a gate electrode 106 formed on the surface of the well region 100 a between the impurity regions 103 a and 104 a with the gate oxide film 105 in between. The gate electrode 106 is made of polycrystal silicon film to which impurities are added, and has gate side walls (side walls) 106 a on its side surfaces. The first to fifth wiring layers 109 a to 109 e made of copper (Cu) or aluminium-copper alloy (AlCu) are stacked on the MOS transistors 107 and 107 a with LTO (Low Temperature Oxidation) film 0.2 μm thick, for example, and interlayer insulating films 108 a to 108 f, each 0.8 μm thick and made of BPSG (Boro-Phospho-Silicate Glass), in between. The wiring layers 109 a to 109 e are electrically connected through via-plug 110 made of tungsten (W) or the like provided in the interlayer insulating films 108 a to 108 e.

[0019] In the manufacturing process of such CMOS circuit, planarization is performed to polish protrusions of each of the interlayer insulating films when each of the interlayer insulating films 108 a to 108 e is formed after the metallic wiring layers 109 a to 109 e are formed respectively. Planarization is also performed to remove metal attached to the surface of the substrate other than a contact hole after the contact hole (contact hole or bear hole) is formed on the interlayer insulating films 108 a to 108 e and then metal such as tungsten is deposited on the surface of the substrate including the contact hole by CVD (Chemical Vapor Deposition).

[0020]FIGS. 13A and 13B show the cross sectional configuration of a composite thin film magnetic head as an example of a thin film magnetic head of the related art. FIG. 13A shows a cross section vertical to the track surface and FIG. 13B shows a cross section parallel to the track surface of the magnetic pole portion. This magnetic head 200 comprises a reproducing head 200A and a recording head 200B.

[0021] The reproducing head 200A comprises a magnetoresistive film 205 made of permalloy (NiFe alloy), for example, formed on a substrate 201 made of altic (alumina titanium carbide; Al2O3-TiC), for example, with an undercoating layer 202 made of alumina (aluminum oxide; Al2O3), for example, a bottom shield layer 203 made of ferrous aluminum silicide (FeAlSi), for example, and a shield gap layer 204 made of aluminum oxide (Al2O3, referred to as alumina in the followings), for example, in between in this order. A lead electrode layer 205 a is also formed on the shield gap layer 204 and is electrically connected to the magnetoresistive film 205. A shield gap layer 106 made of alumina, for example, is stacked on the magnetoresistive film 205 and the lead electrode layer 205 a. In other words, the magnetoresistive film 205 and the lead electrode layer 205 a are buried between the shield gap layers 204 and 206.

[0022] The recording head 200B comprises a top pole 209 formed on the reproducing head 200A with a bottom pole 207 which also works as a top shield layer for the magnetoresistive film 205 (referred to as bottom pole in the followings) and a write gap layer 208 in between. The top pole 209 is divided into two parts: a pole tip 209 a which determines the track width and a top magnetic layer 209 b which works as a yoke. An insulating layer 210 made of alumina is formed on the bottom pole 208. The surface of the insulating layer 210 is planarized to form the same surface as the surface of the pole tip 209 a. Thin film coils 211 and 212 are stacked on the insulating layer 210, and are covered with insulating layers 213 and 214. The top magnetic layer 209 b is formed on the pole tip 209 a and the insulating layers 213 and 214. The top magnetic layer 209 b is covered with an overcoat layer 215. In the recording head 200B, the bottom pole 207 facing the top pole 209 has a trim structure in which part of the surface is processed to be protruded.

[0023] In the reproducing head 200A of such a composite thin film magnetic head, the characteristic of the magnetoresistive element largely depends on the surface of the bottom shield layer 203. Therefore, in general, the bottom shield layer 203 is planarized before these elements are formed. Similarly, the surface of the bottom pole 208 is planarized before the write gap layer 208 is formed in order to improve the performance of the recording head 200B. Further, in the recording head 200B, the top pole 209 is divided into the top pole tip 209 a and the top magnetic layer 209 b in order to form a narrow track. The insulating layer 210 is planarized after the pole tip 209 a is formed.

[0024] In most of the thin film magnetic heads, magnetic materials and insulating materials, metallic materials for coils or other materials are exposed to the surface by planarization. As a result, the planarization process using the polishing apparatus of the related art has serious problems such as flatness, scratches, and recesses between the insulating film and the metallic layer, since magnetic materials and insulating materials or metallic materials are polished at one time.

[0025]FIG. 14 specifically shows the configuration of a platen of a polishing portion and a wafer holder (head portion) as an example of a CMP apparatus of the related art. The CMP apparatus comprises an abrasive pad (abrasive cloth) 301 pasted on a platen 300. The apparatus planarizes the surface of the wafer through polishing the uneven surface of the wafer by pouring slurry with a specific diameter of grains in between a wafer holder 302 and the abrasive pad 301 while the platen 300 and the wafer holder 302 to which a wafer is attached are rotated.

[0026] In such a polishing apparatus, materials with a large frictional drag or materials with a small frictional drag is used as the abrasive pad 301 depending on the intended polishing speed or the amount of polishing. Two-layered pad in which a hard pad and a soft pad are laminated or a single-layered pad using a hard pad or a soft material is used as the abrasive pad 301 depending on its usage. Further, planarization of the wafer is performed by changing the rotation frequency of the wafer holder 302 and the platen 300 or reversing the direction of rotation. Further, the kind of materials of slurry or the diameter of the grains are taken into consideration in order to ensure uniformity in the amount of polishing, the polishing speed, and also the amount of polishing in the wafer.

[0027] With such a method, however, there has been a limit in precision of polishing. Especially the pattern shape in the wafer has been an important factor to determine the uniformity in flatness, as specifically described in the followings.

[0028] First, problems in forming the metallic wiring in a semiconductor integrated circuit of the related art will be described with reference to FIGS. 15A and 15B.

[0029]FIG. 15A shows a state in which an interlayer insulating film 402 about 2 mm thick made of silicon oxide film (SiO2) is formed on a plurality of metallic wiring patterns 401 with a film thickness of 0.7 μm which are formed on a field oxide film 400 formed on a silicon substrate. The interlayer insulating film 402 has protrusions 402 a over a region where the minute metallic wiring patterns 401 are aggregated. FIG. 15B shows a state after planarizing the surface of the interlayer insulating film 402 by the CMP apparatus shown in FIG. 12.

[0030] As seen from FIGS. 15A and 15B, when a wafer including part in which the minute metallic wiring patterns 401 are aggregated (dense region) and other part in which the metallic wiring patterns 401 are not aggregated (empty region) is planarized by the CMP apparatus, the region of the protrusions 402 a where the metallic wiring patterns 401 are aggregated is completely planarized. However, the areas between two dense regions where the wiring metallic patterns 401 are densely formed do not have high flatness.

[0031] In other words, in such a planarization process, the state after planarization varies depending on the metallic wiring patterns in the wafer or the arrangement of the regions where the patterns are aggregated. In general, when the polishing process is performed over the dense region where the minute patterns are densely formed and over an isolated pattern of a minute pattern or a large pattern, the area of contact between the abrasive pad and the protrusions over the patterns in the wafer differs, and thus the polishing speed or the state after planarization differs. The polishing speed of polishing over the isolated minute pattern is greater than that of polishing over the aggregated large patterns. As a result, the film thickness of the interlayer insulating film over the former part becomes different from other parts so that over-etching is required in accordance with the film thickness of the thickest interlayer insulating film at the time of forming contact holes and others in the interlayer insulating film.

[0032] When minute contact holes of 0.5 μm, 0.3 μm, or 0.25 μm, in diameter for example, are formed by dry etching such as RIE (Reactive Ion Etching), a large amount of over-etching is required. As a result, ohmic contact resistance between the contact holes or the like and the electrode wiring becomes large and thus the performance of many of the device characteristic deteriorates, which ultimately results in decreasing the yields. Further, as mentioned above, when the polishing process by CMP is performed over the region including part in which lots of minute metallic patterns are aggregated and other part in which metallic wiring patterns are not aggregated, the part in which the metallic wiring patterns are aggregated is precisely planarized, while the part between two regions of the aggregated wiring patterns does not have high flatness. This becomes worse as the number of the wiring layers increases to four, five or more.

[0033] As described, the CMP apparatus of the related art has a problem that the CMP apparatus can achieve an excellent flatness locally but cannot attain sufficient flatness over a wide area. As a result, in the manufacturing process of the semiconductor integrated circuit of the related art, the wiring layer provided on the region with low flatness have breaks or failures caused by electro-migration if the width of the metallic wiring pattern is small.

[0034] Next, specific problems in the manufacturing process of a thin film magnetic head will be described with reference to FIGS. 16A to 16C. The figures show the thin film magnetic head viewed from the ABS side. As shown in FIG. 16A, an insulating layer 501 about 3 to 5 μm thick made of alumina is deposited on a substrate 500 made of altic by sputtering, for example. Next, a bottom shield layer 502 about 2 to 3 μm thick for the reproducing head made of a magnetic material such as permalloy (NiFe) is formed on the insulating layer 501 by plating, for example. Then an insulating layer 503 about 3 to 4 μm thick made of alumina is formed on the bottom shield layer 502. The insulating layer 503 has protrusions 503 a over the bottom shield layer 502.

[0035]FIG. 16B shows a state after the surface of the insulating layer 503 is planarized by a polishing apparatus. In such a thin film magnetic head, it is necessary to polish the surface of the insulating layer 503 to reach the bottom shield layer 502 so as to make the bottom shield layer 502 exposed in the surface of the insulating layer 503. As a result, there are steps between the insulating layer 503 and the bottom shield layer 502 so that either the insulating layer 503 or the bottom shield layer 502 has a recessed structure which partially includes recesses. The sizes of the recesses in such a case reaches 0.15 to 0.3 μm, sometimes 0.4 μm or more.

[0036] As shown in FIG. 16C, after a bottom shield gap film 504, a magnetoresistive film 505 and its lead electrode layer 506, a top shield gap film 507 and a top shield-cum-bottom pole 508 are formed in a thickness of about 2 to 4 μm, another insulating layer 509 made of alumina is formed in a thickness of 3 to 5 μm, and then the surface of the insulating layer 509 is polished by the polishing apparatus. The recesses are also formed at this time. Further, after a write gap film 510 is formed in a thickness of 0.2 to 0.3 μm, a pole tip 511 is formed in a thickness of 2 to 3 μm. Again, an insulating layer 512 is formed in a thickness of 3 to 4 μm and then polished. At this time, the recesses of 0.2 to 0.4 μm are also formed. The manufacturing process of a thin film magnetic head is completed after forming a thin film coil (not shown in figure), a top magnetic layer (top pole) 513, an overcoat layer (not shown in figure) and so on.

[0037] As described, the manufacturing process of a thin film magnetic head is a little different from that of a semiconductor integrated circuit mentioned above. That is, the material to be polished is different and, in general, a plurality of layers made of materials with different hardness are polished in a thin film magnetic head. For example, the structure in which an insulating layer made of alumina and a thin film coil or the like made of permalloy (NiFe) or copper (Cu) are exposed together in the surface of the wafer. Accordingly, it is necessary to complete the CMP process taking the materials and the polishing speed into consideration. It is extremely difficult to control uniformity of the amount of polishing of the whole wafer since the polishing speed varies because of the pattern dependence.

[0038] Further, excellent uniformity in thickness of the bottom shield layer, the top shield layer, the pole tip and so on in the wafer after being polished is required, in addition to controlling the amount of polishing by CMP. The uniformity in thickness largely contributes to the performance of the thin film magnetic head so that precise control of the film thickness is required.

[0039] With the polishing apparatus of the related art, however, it has not been possible to achieve a CMP process, in which the film thickness of the insulating layer made of such as alumina and the magnetic layer (shield magnetic film or recording pole) made of such as permalloy (NiFe) is precisely controlled. The reason is because it is extremely difficult to control the polishing speed of the substances with different hardness such as the insulating layer made of alumina and metal such as permalloy, as described, and thus recesses are formed between the insulating layer and the top or bottom shield layers when the bottom shield layer, the top shield layer and the pole tip are polished. This has been a main factor for suppressing the performance of the thin film magnetic head.

SUMMARY OF THE INVENTION

[0040] The invention is designed to overcome foregoing problems. An object of the invention is to provide a polishing apparatus and a polishing method which can perform a planarization process with high precision in accordance with a scale-down of a device such as a semiconductor device or a thin film magnetic head.

[0041] Another object of the invention is to provide a manufacturing method of a semiconductor device for performing a planarization process with high precision in accordance with a scale-down.

[0042] Still another object of the invention is to provide a manufacturing method of a thin film magnetic head for performing a planarization process with high precision in accordance with a scale-down.

[0043] A polishing apparatus of the invention comprises a plurality of polishing portions for performing polishing processing of different degrees on one subject of polishing.

[0044] In the polishing apparatus of the invention, it is desired that the polishing portions include at least a first polishing portion for performing roughing on the subject of polishing and a second polishing portion for performing finishing on the subject which has been roughed by the first polishing portion.

[0045] In the polishing apparatus, roughing is performed on the subject of polishing in a first polishing portion, and then, in a second polishing portion, finishing is performed on the subject of polishing which has been roughed.

[0046] Further, the polishing apparatus of the invention may further include a third polishing portion comprising at least one polishing portion for performing medium polishing on the subject which has been roughed by the first polishing portion, the third polishing portion provided between the first polishing portion and the second polishing portion.

[0047] The polishing apparatus of the invention may have a configuration in which each of the polishing portions comprises a rotatable platen, and an abrasive pad with a laminated structure of a plurality of layers which have different hardness is pasted on at least one of the platens.

[0048] The polishing apparatus of the invention may have a configuration in which the abrasive pad has a two-layered structure with one layer for polishing a subject being formed of a hard resin and the other layer being formed of a softer material than the one layer. The one layer may be formed of polyurethane foam.

[0049] The polishing apparatus of the invention may have a configuration in which an abrasive pad with a single-layered structure is pasted on at least one of the other platens.

[0050] The polishing apparatus of the invention may have a configuration in which at least one of the platens includes a grinder on at least part of the polishing surface. Specifically, the grinder may take a disk-like shape or a ring shape and have a thickness of about 0.5 mm to about 5.0 mm. The grinder may include diamond grains and the grinder including diamonds may be formed with resin being a base. Examples of the resin as a base include a phenolic resin, an epoxy resin and a glass resin. Generally, a grinder requires careful handling because it may be as thin as 0.01 mm or less. The grinder of the preferred embodiment has a thickness of about 0.5 mm to about 5.0 mm and a certain hardness. Accordingly, the grinder is easier to handle or replace. Furthermore, since the grinder preferably has a thickness of about 0.5 mm to about 5.0 mm, diamond grains my be buried within the thickness in a stable manner to promote polishing.

[0051] In the polishing apparatus of the invention, the grinder may be formed of a hard resin. As the resin, a polyurethane foam is used, for example.

[0052] In the polishing apparatus of the invention, roughing may be performed on the subject of polishing using the grinder in the first polishing portion. Further, medium polishing may be performed on the subject of polishing in the third polishing portion using a grinder with smaller roughness than that of the first polishing portion, and then finishing may be performed on the subject of polishing in the second polishing portion using a grinder with smaller roughness than that of the third polishing portion. Otherwise, medium polishing may be performed on the subject of polishing in the third polishing portion using a grinder with smaller roughness than that of the first polishing portion, and then finishing may be performed on the subject of polishing in the second polishing portion using an abrasive pad with smaller roughness than that of the third polishing portion. Alternatively, medium polishing may be performed on the subject of polishing in the third polishing portion using an abrasive pad with smaller roughness than that of the first polishing portion, and then finishing may be performed on the subject of polishing in the second polishing portion using an abrasive pad with smaller roughness than that of the third polishing portion.

[0053] In the polishing apparatus of the invention, the abrasive pad of the second polishing portion may be an abrasive pad with the laminated structure described above.

[0054] Further, in the polishing apparatus of the invention, roughing may be performed on the subject of polishing in the first polishing portion using the above-mentioned grinder, and then finishing may be performed on the subject of polishing in the second polishing portion using an abrasive pad with smaller roughness than that of the first polishing portion.

[0055] In the polishing apparatus of the invention, roughing may be performed on the subject of polishing in the first polishing portion using the above-polishing in the second polishing portion using an abrasive pad with smaller roughness than that of the first polishing portion. The abrasive pad of the second polishing portion may be the polishing pad with the above mentioned laminated structure.

[0056] In the polishing apparatus of the invention, slurry may be used together with the abrasive pad in the second polishing portion. The slurry including alumina grains is used at this time.

[0057] The polishing apparatus of the invention may further include a cleaning portion for performing cleaning on the subject of polishing which has been finished in the second polishing portion. The cleaning portion may comprise a cleaning pad made of a soft brush.

[0058] In the polishing apparatus of the invention, for example, a wafer for a semiconductor integrated circuit or a wafer for a thin film magnetic head is used as the subject of polishing.

[0059] In the polishing apparatus of the invention, each of the platens of the respective polishing portions is stored in a pedestal and processing may be performed on the subject of polishing in order in the polishing portions.

[0060] A polishing method of the invention is for polishing and planarizing a subject of polishing and includes at least a first polishing step of performing roughing on the subject of polishing and a second polishing step of performing finishing after the first polishing step on the subject of polishing which has been roughed.

[0061] The polishing method of the invention may further include a third polishing step including at least one polishing step for performing medium polishing before the second polishing step on the subject of polishing which has been roughed in the first polishing step.

[0062] In the polishing method of the invention, the polishing steps may be performed in a plurality of polishing portions included in one pedestal.

[0063] The method of manufacturing a semiconductor device of the invention includes a planarizing step for polishing and planarizing a wafer for a semiconductor integrated circuit, wherein the planarizing step is performed using the polishing apparatus of the invention. A polishing surface may be a surface of an interlayer insulating film formed on a metallic wiring layer having aggregated or isolated patterns provided on a semiconductor wafer, for example.

[0064] The method of manufacturing a thin film magnetic head of the invention includes a planarizing step for polishing and planarizing a thin film magnetic head, wherein the planarizing step is performed using the polishing apparatus of the invention. A polishing surface may be a surface of an insulating layer formed to cover one of two shield layers which sandwich a magnetoresistive element included in a reproducing head. The polishing surface may also be a surface of an insulating layer formed to cover a pole tip of a recording head, the recording head comprising a magnetic pole which is divided into the pole tip and a magnetic layer.

[0065] Other and further objects, features and advantages of the invention will appear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0066]FIG. 1 is a perspective view showing a configuration of a polishing apparatus according to a first embodiment of the invention.

[0067]FIG. 2 is a figure showing a cross sectional configuration of the polishing portion taken along the line II-II in FIG. 1.

[0068]FIG. 3 is a cross section showing a configuration of an abrasive pad in the polishing apparatus shown in FIG. 1.

[0069]FIG. 4 is a perspective view showing a configuration of the polishing apparatus according to a second embodiment of the invention.

[0070]FIGS. 5A and 5B are cross sections for describing a planarization process of a semiconductor integrated circuit by the polishing apparatus of the invention.

[0071]FIGS. 6A, 6B and 6C are cross sections for describing a planarization process of a thin film magnetic head by the polishing apparatus of the invention.

[0072]FIG. 7 is a characteristic diagram for describing the polishing result using the polishing apparatus of the related art.

[0073]FIGS. 8A and 8B are characteristic diagrams for describing the polishing result using the polishing apparatus of the invention; FIG. 8A shows the result of polishing alumina and FIG. 8B shows the result of polishing permalloy.

[0074]FIG. 9 is a plan view for describing the measuring point of the wafer in the characteristic diagrams shown in FIGS. 8A and 8B.

[0075]FIG. 10 is a perspective view for describing an example of grinder used in the polishing apparatus of the invention.

[0076]FIG. 11 is a plan view for describing a schematic configuration of the apparatus according to still another embodiment of the invention.

[0077]FIG. 12 is a cross section of a CMOS circuit as an example to which a planarization process by the polishing apparatus is applied.

[0078]FIG. 13A is a cross section of a thin film magnetic head as another example to which the planarization process by the polishing apparatus is applied.

[0079]FIG. 13B is a cross section of the thin film magnetic head shown in FIG. 13A viewed from the ABS side.

[0080]FIG. 14 is a perspective view showing a configuration of a polishing apparatus of the related art.

[0081]FIGS. 15A and 15B are cross sections for describing problems in using the polishing apparatus of the related art in a planarization process of a semiconductor integrated circuit.

[0082]FIGS. 16A, 16B and 16C are cross sections for describing problems in using the polishing apparatus of the related art in a planarization process of a thin film magnetic head.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0083] Preferred embodiments of the invention will be described in the followings with reference to corresponding figures.

[0084] [First Embodiment]

[0085]FIG. 1 shows a configuration of a polishing apparatus 1 according to a first embodiment of the invention. The polishing apparatus 1 is for polishing a subject of polishing such as the surfaces of wafers and comprises a pedestal 10. A plurality of (three, for example, in this embodiment) polishing portions 11A to 11C, and a cleaning portion 11D are provided on the pedestal 10. The polishing portions 11A to 11C and the cleaning portion 11D comprise platens 12 a to 12 d respectively. The platens 12 a to 12 d are placed on the surface of the pedestal 10 in a rotatable state. The platens 12 a to 12 d are coupled to a rotating device (not shown in figure) provided under the pedestal 10 through openings (not shown in figure) provided in the pedestal 10. The platens 12 a to 12 d are made to rotate with a predetermined speed in a counterclockwise direction when viewed from the above.

[0086] Four wafer holders (heads) 14 are placed on the pedestal 10 facing the platens 12 a to 12 d. The wafer holders 14 comprise a holder 14 a (not shown in FIG. 1, see FIG. 2) for holding wafers. The wafer holder 14 a is also made to rotate with a predetermined speed in a clockwise direction when viewed from the above by a spindle motor (not shown in figure) around a rotating shaft 14 b. The surfaces of the platens 12 a to 12 d in the polishing portions 11A to 11C and the cleaning portion 11D respectively have different roughness and hardness from one another. The wafer to be polished, together with the wafer holder 14 a, is moved to a position facing the platens 12 a to 12 d of the polishing portions 11A to 11C and the cleaning portion 11D in this order to be polished and cleaned to a different degree.

[0087] At least part of the polishing surface of the platen 12 a, or the whole surface, is composed of a grinder. As the grinder, resin such as phenol resin is used as a base to which diamond grains with the diameter being 1,000th to 3000th, 5,000th or 10,000th are scatteringly fixed. The grinder takes a round or disk-like shape and has a thickness of about 0.5 mm to about 5.0 mm and a cerain hardness, for example. The grinder may be a diamond grinder (vitrified) in which a glass resin is used as a base. It may be formed only of hard resin such as porous polyurethane foam, phenol resin or epoxy resin without using diamond grains.

[0088]FIG. 2 shows an example of a cross sectional configuration of the polishing portion 11A shown in FIG. 1 taken along the line II-II. In FIG. 2, the holder 14 a of the wafer holders 14 is formed of porous chuck. A wafer W is adsorbed and held by the holder 14 a through the cavity 14 c provided in the wafer holder 14 being evacuated in the direction shown by an arrow a in the figure. In the polishing portion 11A, a lubricant 16 is supplied from a nozzle 15. Examples of the lubricants are pure water, oil, isopropyl alcohol, alumina slurry, silica slurry and the like.

[0089] In the embodiment, first, polishing (roughing) of the wafer W is performed by the platen 12 a in the polishing portion 11A while supplying lubricator 16 from the nozzle 15. Thus the protrusions of the insulating film covering lots of different patterns in the wafer such as aggregated minute wiring patterns, a large pattern or an isolated pattern are made to be removed flat. In the polishing portion 11A, the platen 12 a is formed of a grinder and thus has a hard polishing surface. As a result, there are scratches being slightly generated, but the polishing surface exhibits no pattern dependence. The polishing portion 11A corresponds to the “first polishing portion” of the invention.

[0090] The abrasive pad 13 b with a single-layered structure made of, for example, a hard polyurethane form is pasted on the surface of the platen 12 b in the polishing portion 11B. Polishing is performed by the abrasive pad 13 b using an abrasive liquid supplied from a nozzle (not shown in figure). Examples of the slurry included in the abrasive liquid are alumina, silica and a mixture of both. The polishing portion 11B performs the medium polishing (that is, polishing with a degree between the first roughing and the last finishing) through removing the scratches or the polishing distortion slightly generated in the polishing portion 11 A by the abrasive pad 13 b. The polishing portion 11B corresponds to an embodiment of the “third polishing portion” of the invention. Specifically, in the thin film magnetic head, the insulating layer made of alumina is made to be polished in the polishing portion 11B until right before the magnetic layer made of permalloy or the like (shield magnetic film or recording pole) is exposed to the surface of the wafer. The third polishing portion may be composed of a polishing portion for performing two or more degrees of polishing depending on the application.

[0091] The abrasive pad 13 c with a structure of a plurality of (two, for example) layers is pasted on the surface of the platen 12 c in the polishing portion 11 C. FIG. 3 shows an example of a cross sectional configuration of the abrasive pad 13 c including the platen 12 c.

[0092] The abrasive pad 13 c has a two-layered structure of a surface layer 13 c 1 and a bottom layer 13 c 2. The surface layer 13 c 1 is formed of a porous polyurethane form, for example, while the bottom layer 13 c 2 is formed of an elastic material such as polyurethane or a gum rubber, which is softer than the surface layer 13 c 1, or of a hard material such as ceramic or plastic. The polishing portion 11C performs finishing through lightly polishing the surface of the wafer by the abrasive pad 13 c. The polishing portion 11C corresponds to an embodiment of the “second polishing portion” of the invention. Also, the same abrasive liquid including slurry as in the polishing 11B is supplied from the nozzle 15 to the abrasive pad 13 c.

[0093] A cleaning pad 13 d with a single-layered structure including a brush with long pile is pasted on the surface of the platen 12 d in the cleaning portion 11D. The cleaning portion 11D completely removes (cleans) the contamination left by the micro scratches or slurry generated in the prior process by the cleaning pad 13 d using pure water or alcohol as the lubricant. The cleaning portion 11D corresponds to the “cleaning portion” of the invention. The cleaning portion may be formed of two or more cleaning portions for performing different degrees of cleaning.

[0094] Next, operation of the polishing apparatus 1 will be described.

[0095] In polishing portions 11A to 11C, and the cleaning portion 1ID of the polishing apparatus 1, the platens 12 a to 12 d and the wafer holder 14 for holding the wafer W rotates in the reverse direction of each other. The wafer W as a subject of polishing, together with the wafer holder 14 a, is moved to a position facing the platens 12 a tol2 c of the polishing portions 11A to 11C and to the platen 12 d of the cleaning portion 11D in this order so as to be polished and cleaned to a different degree.

[0096] First, in the polishing portion 11A, the protrusions of the insulating film covering lots of different patterns in the wafer (for example, the aggregated minute wiring patterns, a large pattern or an isolated pattern) are removed (roughed) flat by the platen 12 a made of a hard grinder. In this case, the polishing surface of the wafer W exhibits no pattern dependence since the polishing surface is hard.

[0097] The wafer W to which roughing has been performed in the polishing portion 11A is then moved to the polishing portion 11B. In the polishing portion 11B, scratches and polishing distortion slightly generated in the wafer by the platen 12 a are removed (medium polishing) by the hard abrasive pad 13 b with a single-layered structure. Specifically, in the thin film magnetic head, the insulating layer made of alumina is polished until right before the magnetic layer made of permalloy or the like (shield magnetic film or recording pole) is exposed in the surface of the wafer.

[0098] The wafer W to which the medium polishing has been performed in the polishing portion 11B is then moved to the polishing portion 11C. In the polishing portion 11C, finishing is performed by the abrasive pad 13 c with a two-layered structure. In the abrasive pad 13 c, the surface layer 13 c 1 made of a hard polyurethane form or the like is supported by the bottom layer 13 c 2 made of a softer material than the surface layer 13 c 1. Therefore, the area between the surface of the wafer W and the polishing surface can be made flat. In the process, few scratches or the like are generated on the surface layer of the metallic layer such as coil made of permalloy or copper in the manufacturing process of the thin film magnetic head, for example. Even if there are scratches generated, the scratches are not so serious as to give a damage which is not restorable in the later process.

[0099] In the polishing portion 11C, the wafer W to which finishing has been performed is then moved to the cleaning portion 11D. In the cleaning portion 11D, the contamination left by the micro scratches or slurry generated in the prior process are completely cleaned together with pure water as the lubricant by the cleaning pad 13 d. Thereby, the final finishing is performed and a series of the planarization process is completed.

[0100] As described, the polishing apparatus 1 according to the embodiment comprises three polishing portions 11A to 11C. Roughing, medium polishing and finishing of the wafer W are performed in the polishing portions 11A to 11C respectively to planarize the wafer W. In other words, the wafer W is roughly polished by the platen 12 a made of rough and hard grinder in the polishing portion 11 A, and then is medium-polished by the relatively hard abrasive pad 13 b in the polishing portion 11B. Thereby, protrusions of the wafer W are removed without large scratches or cracks being generated while the polishing surface of the wafer W exhibits no pattern dependence. Further, finishing is performed by the fine soft abrasive pad 13 c in the polishing portion 11C. At last, micro cracks and scratches are completely removed by the soft cleaning pad 13 d with long pile in the cleaning portion 11D.

[0101] In the embodiment, the planarization process can be thus precisely performed so that performance of the semiconductor integrated circuit and the composite thin film magnetic head can be improved while yield of manufacturing is improved.

[0102] Further, in the embodiment, four wafer holders 14 sequentially move to the polishing portions 11A to 11C and the cleaning portion 11D in order so that processing of the wafer W can be continuously performed. At this time, appropriate polishing processing depending on the subject of processing can be performed on each wafer if the processing period is set separately for each of the polishing portions 11A to 11C and the cleaning portion 11D. When the processing period of the wafer does not meet mutually in each portion, the wafer may be made stood by in the polishing portions 11A to 11C and the cleaning portion 11D.

[0103] Second Embodiment]

[0104]FIG. 4 shows a configuration of a polishing apparatus 2 according to a second embodiment of the invention. Identical reference numerals are given to the parts of the configuration identical to the first embodiment and the description will be omitted.

[0105] The polishing apparatus 2 comprises two polishing portions 21A and 21B, and a cleaning portion 21C. The polishing portions 21A, 21B and the cleaning portion 21C comprise platens 22 a to 22 c respectively, and wafer holders (heads) 24 are placed facing each of the platens 22 a and 22 c. The surfaces of the platens 22 a to 22 c have different roughness from one another. The wafer W, together with the wafer holder 24, is moved to the polishing portions 21A, 21B and to the cleaning portion 21C in this order to be polished and cleaned to a different degree.

[0106] A hard polishing abrasive pad 23 a with a single-layered structure made of a hard resin such as a polyurethane form is pasted on the surface of the platen 22 a in the polishing portion 21A. The polishing liquid including slurry is supplied from a nozzle (not shown in figure) to the abrasive pad 23 a. Examples of the slurry are alumina, silica and a mixture of both. In the polishing portion 21A, the platen 22 a may also be formed of a grinder and perform polishing using the lubricant as in the first embodiment. The polishing portion 21A first performs polishing to remove protrusions of the insulating film covering lots of different patterns in the wafer (the aggregated minute wiring patterns, a large pattern or an isolated pattern, for example) by the platen 22 a. In the embodiment, the polishing portion 21A corresponds to another embodiment of the “first polishing portion” of the invention. The polishing surface of the platen 22 a is the hard abrasive pad 23 a so that the polishing surface of the wafer W exhibits no pattern dependence. Specifically, in the thin film magnetic head, the insulating layer made of alumina is made to be polished in the polishing portion 21A until right before the magnetic layer made of permalloy or the like (shield magnetic film or recording pole) is exposed in the surface of the wafer as in the polishing portion 11B according to the first embodiment.

[0107] An abrasive pad 23 b with a two-layered structure is pasted on the surface of the platen 22 b in the polishing portion 21B. The abrasive pad 23 b has the same configuration as that of the abrasive pad 13 c of the first embodiment, for example. The polishing portion 21B performs finishing through removing micro scratches and polishing distortion slightly generated in the polishing portion 21A by lightly polishing the surface of the wafer by the abrasive pad 23 b. The polishing portion 21B corresponds to another embodiment of the “second polishing portion” of the invention. The polishing liquid including slurry is supplied from a nozzle to the abrasive pad 23 b. When the subject of polishing is a thin film magnetic head, the film thickness of the shield pole, the recording pole or the like after being polished in the polishing portion 21A is precisely controlled in the polishing portion 21B and scratches on the surface of the magnetic layer made of permalloy are removed while recesses being 0.05 μm or less.

[0108] A cleaning pad 23 c having the same configuration as that of the cleaning pad 11 d of the first embodiment, for example, is pasted on the surface of the platen 22 c in the cleaning portion 21C. The cleaning portion 21C completely removes (cleans) the contamination left by the micro scratches or slurry generated in the prior process by the cleaning pad 23 c using pure water or alcohol as the lubricant. The cleaning portion 21C corresponds to another embodiment of the “cleaning portion” of the invention.

[0109] First, in the polishing portion 21A of the polishing apparatus 2 according to the embodiment, roughing is performed by the abrasive pad 23 a formed of, for example, a hard polyurethane form. Thus, protrusions of the insulating film covering lots of different patterns in the wafer are removed flat. The wafer W to which roughing has been performed in the polishing portion 21A is moved to the polishing portion 21B.

[0110] In the polishing portion 21B, finishing is performed through removing micro scratches and polishing distortion slightly generated in the wafer W in the polishing portion 21A by the abrasive pad 23 b with a two-layered structure. Specifically, in the thin film magnetic head, the insulating layer made of alumina is made to be polished in the polishing portion 21A until right before the shield pole or the recording pole made of permalloy or the like is exposed in the surface of the wafer.

[0111] Finally, when finishing is performed to the wafer W in the polishing portion 21B, in the cleaning portion 21C, the contamination left by the micro scratches or slurry generated in the prior process is completely cleaned by the cleaning pad 23 c.

[0112] As described, in the polishing apparatus 2 according to the embodiment, roughing and finishing are performed in the two polishing portions 21A and 21B by the abrasive pads 23 a and 23 b having different roughness and hardness from each other. Further, cleaning is performed in the cleaning portion 21C. As a result, in the embodiment, the planarization of the wafer can be also precisely performed so that performance of the devices such as the semiconductor integrated circuit and the composite thin film magnetic head can be improved while yield of manufacturing is improved.

[0113] Next, a planarization process for a multi level interconnect structure in the semiconductor integrated circuit and a planarization process of the shield layer of the thin film magnetic head and the pole tip of the top pole will be described as examples of specific applications of the polishing apparatuses 1 and 2.

[0114] First, FIGS. 5A and 5B show an example in which the apparatus is applied to a planarization process of a multi level interconnect structure of a semiconductor integrated circuit. FIG. 5A shows a state in which an interlayer insulating film 32 about 2 μm thick made of silicon oxide film (SiO2) is formed on a plurality of metallic wiring patterns 31 with a thickness of 0.7 μm, for example, on the field oxide film 30 which is formed on a silicon substrate. The interlayer insulating film 32 has protrusions 32 a over the region where minute metallic wiring patterns 31 are aggregated. FIG. 5B shows a state after the surface is planarized by the above-mentioned polishing apparatuses 1 or 2.

[0115] As evident from the figure, in the embodiment, not only the protrusions 32 a over the aggregated metallic wiring patterns 31 but areas between two regions where the metallic wiring patterns 31 are aggregated are also precisely planarized. Accordingly, the wiring layers thereon (not shown in figure) do not have breaks or failures caused by electro-migration. As a result, in a multi level interconnect structure of a semiconductor integrated circuit, planarization processing without pattern dependence can be performed while reliability of the device and yield of manufacturing are remarkably improved.

[0116] Next, FIGS. 6A to 6C show an example in which the apparatus is applied to a planarization process of the shield layer of the thin film magnetic head and the pole tip of the top pole. As shown in FIG. 6A, an insulating layer 41 about 3 to 5 μm thick made of alumina is formed on a substrate 40 made of altic by sputtering, for example. Then a bottom shield layer 42 about 2 to 3 μm thick for a reproducing head made of magnetic materials such as permalloy (NiFe) is formed on the insulating layer 41 by plating, for example. An insulating layer 43 about 3 to 4 μm thick made of alumina is formed on the bottom shield layer 42. The insulating layer 43 has protrusions 43 a over the bottom shield layer 42.

[0117]FIG. 6B shows a state after the surface of the insulating layer 43 is planarized by the above-mentioned polishing apparatuses 1 or 2. In such a thin film magnetic head, the surface is polished to reach the bottom shield layer 42 so that the bottom shield layer 42 is exposed in the surface of the insulating layer 43. In the related art, as described above, there are steps between the insulating layer 43 and the bottom shield layer 42 so that either the insulating layer 43 or the bottom shield layer 42 has a recessed structure. In contrast, in the embodiment, polishing processing divided into a plurality of steps with different polishing hardness is performed so that planarization processing without pattern dependence can be performed. In addition, there are fewer recesses between the insulating layer 43 and the bottom shield layer 42, and polishing speed and the thickness of the remained film of both layers are controlled more precisely.

[0118] In the embodiment, then, as shown in FIG. 6C, a bottom shield gap film 44, a magnetoresistive film 45, a lead layer (lead) 46 connected to the magnetoresistive film 45, a top shield gap film 47 and a top shield-cum-bottom pole 48 are formed in a thickness of about 2 to 4 μm. Then, an insulating layer 49 about 3 to 5 μm thick made of alumina is formed and the surface of the insulating layer 49 is polished by the polishing apparatuses 1 or 2. In the embodiment, recesses are rarely formed also at this time. Further, after a write gap film 50 in a thickness of 0.2 to 0.3 μm is formed, a pole tip 51 a in a thickness of 2 to 3 μm is formed. An insulating layer in a thickness of 3 to 4 μm is formed thereon and then polished. In the embodiment, recesses are rarely formed also at this time. At last, a thin film coil (not shown in figure), a top magnetic layer (top pole) 51 b, an over coat layer (not shown in figure) and the like are formed and the manufacturing process of the thin film magnetic head is completed.

[0119] As described, it is necessary to control the amount of polishing by the polishing apparatus and to keep excellent uniformity in thickness of bottom shield layer, the top shield layer and the pole tip in the wafer after being polished in order to improve performance of the thin film magnetic head. In the polishing apparatus of the related art, however, when polishing the bottom shield layer, the top shield layer or the pole tip, recesses are formed between the insulating layer and the top or bottom shield layers or the pole tip, which results in deterioration of the performance of the thin film magnetic head. In contrast, in the embodiment, a plurality of polishing processing with different polishing degrees are performed so that the polishing speed of the insulating layer and the magnetic layer exposed in the surface of the insulating layer is controlled more precisely. The uniformity in thickness of the layers in the wafer is also improved and there is no scratches or the like on the surface of the magnetic layer. Further recesses become small and reproducing performance is improved. Accordingly, it becomes easier to form a narrow track, which is an important process for manufacturing a thin film magnetic head. Especially, performance of the recording head is remarkably improved.

EXAMPLE

[0120] In FIG. 7, “a” shows data of polishing an alumina insulating film about 6 μm thick formed on a permalloy pattern about 3.0 μm thick of a shield layer by about 2 μm with 3000th vitrified grinder by the method of the related art in the thin film magnetic head, and “b” shows data of measuring the size of the steps after polishing the surface by 3 μm using an abrasive pad with a two-layered structure made of IC 1000 and Suba 400 of the related art. In FIG. 7, the horizontal axis represents the measuring position in the wafer (mm) and the vertical axis represents the thickness of the remained film (nm). In the result “a”, the shield layer made of permalloy was not exposed and existence of scratches on the surface was unknown. In other experiments, however, lots of scratches were found on the surface of the shield layer when the shield layer made of permalloy was exposed. The result “b” is the one measuring the size of the steps of the surface of the wafer when the shield layer made of permalloy was exposed. Micro scratches were found here and there on the surface of the shield layer, depending on selection of slurry. These scratches were, however, not serious. Recesses were as relatively large as 150 to 300 nm depending on selection of slurry.

[0121] In contrast, FIGS. 8A and 8B show the result of performing planarization by the polishing apparatus 1 according to the embodiment. In the FIGS. 8A and 8B, numerals from 1 to 9 on the horizontal axis represent the horizontal position and correspond to the measuring position in the wafer W shown in FIG. 9. The 3000th resin was used as the grinder. As a sample, an insulating film 4.5 μm thick made of alumina was formed on a magnetic layer 3 μm thick made of permalloy and the insulating film was planarized by the polishing apparatus 1. FIG. 8A shows data of the thickness of the remained film of the insulating layer made of alumina after being polished by 1.5 μm. In the figure, “a” represents the original film thickness of the insulating layer, “b” represents the film thickness of the insulating layer after being polished and “c” represents the amount of polishing performed on the insulating layer.

[0122] On the other hand, FIG. 8B shows data of measuring the thickness of the remained film of the magnetic layer made of permalloy after being polished by 1.5 μm. In the figure, “a” represents the original film thickness of the insulating layer, “b” represents the film thickness of the insulating layer after being polished and “c” represents the amount of recesses. It is evident from these that the film thickness becomes constant all over the wafer, which means planarization is precisely performed, when the polishing apparatus 1 according to the embodiment is used. Further, recesses between the insulating film made of alumina and the shield layer made of permalloy are all suppressed to 50 μm or less.

[0123] The invention has been described by referring to the embodiments and the example. However, the invention is not limited to the embodiments and the example but various modifications are possible. The number of the polishing portions is three in the first embodiment and two in the second embodiment. However, any number equal to or more than two of the polishing portions may be provided. Specifically, the third polishing portion which performs medium polishing may comprise a plurality of polishing portions for performing different degrees of polishing. Further, combination of the grinder and the abrasive pad or the like is not limited to the above-mentioned embodiments but various combinations are also possible. The point is to continuously perform rough polishing and fine polishing in order in a plurality of polishing portions in one apparatus.

[0124] Further, although moving the wafer W between each two of the polishing portions and the cleaning portion is made to be performed by rotating the wafer holder 14 in the above-mentioned embodiments, it may be performed by rotating the pedestal 1 instead.

[0125] Although disk-shaped grinders are used as the grinders for performing roughing in the above-mentioned embodiments, a ring-shaped (or cup-shaped) grinder 60 may be used for polishing the surface of the wafer W as shown in FIG. 10. At this time, the grinder 60 itself rotates with rotating means (not shown in figure) and is moved relative to the surface of the wafer W by moving means (not shown in figure) in the direction shown by an arrow in the figure, and polishes the whole surface of the wafer W.

[0126] Further, although one subject of polishing is polished in the first to third polishing portions in order in the embodiments, it is possible to perform the same type of polishing on two or more subjects simultaneously in each of the first to third polishing portions so that a plurality of subjects of polishing can be simultaneously processed in order to improve the productivity.

[0127] Moreover, although the polishing portions and the cleaning portion are formed on one body in the embodiments, they may be formed as separate apparatuses. FIG. 11 shows one example in which a polishing apparatus 70 comprising three polishing portions 71A to 71C, and a cleaning apparatus 80 comprising two cleaning portions 81A, 81B with different degrees of cleaning and a drying portion 81C are connected by an underwater elevator 90. The polishing portions 71A to 71C in the polishing apparatus 70 are composed of a platen 72 and a waferholder 73 and correspond to the polishing portions 11A to 11C of the first embodiment. In the polishing apparatus 70, the wafer W sent in through a loader 74 is moved to each of the polishing portions 71A to 71C by an arm robot 75 to receive roughing, medium polishing and finishing. The wafer to which finishing has been performed is moved in a wet state to the cleaning apparatus 80 by the underwater elevator 90. In the cleaning portion 80, the wafer W is roughly cleaned in the cleaning portion 81A, finely cleaned by the cleaning portion 81B and spin-dried in the drying portion 81C in order. At last, the wafer W is taken out from the cleaning apparatus 80 through an unloader 82.

[0128] In the invention, the subject of polishing is not limited to the ones mentioned in the embodiments but may be other parts of wafers in a semiconductor integrated circuit or a thin film magnetic head, or other devices. Specifically, in a case of a thin film magnetic head, the polishing apparatus and the polishing method of the invention is applicable to the polishing of ABS in a final process mentioned above to adjust throat height.

[0129] As described, according to the polishing apparatus and the polishing method of the invention, a plurality of polishing processing from roughing to fine finishing can be performed in order since polishing processing with different degrees is performed on one subject of polishing. As a result, the planarization process can be precisely performed and precision of microfabrication of the semiconductor integrated circuit and the thin film magnetic head can be improved while yield of manufacturing is improved.

[0130] Further, according to the method of manufacturing a semiconductor device of the invention, precision of microfabrication and yield of manufacturing are improved since the planarization process is performed using the polishing apparatus of the invention.

[0131] Moreover, according to the method of manufacturing a thin film magnetic head, precision of microfabrication and yield of manufacturing are improved since the planarization process is performed using the polishing apparatus of the invention.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7815492 *Mar 19, 2007Oct 19, 2010Tokyo Electron LimitedSurface treatment method
US8348720Jun 27, 2007Jan 8, 2013Rubicon Technology, Inc.Ultra-flat, high throughput wafer lapping process
US8480456Nov 28, 2012Jul 9, 2013Rubicon Technology, Inc.Ultra-flat, high throughput wafer lapping process
US8623136Feb 1, 2013Jan 7, 2014Rubicon Technology, Inc.Asymmetrical wafer configurations and method for creating the same
US8657648 *Oct 12, 2011Feb 25, 2014Disco CorporationProcessing apparatus having four processing units
US8734207Jun 6, 2013May 27, 2014Rubicon Technology, Inc.Ultra-flat, high throughput wafer lapping process
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Classifications
U.S. Classification451/66, 451/288
International ClassificationB24B37/04
Cooperative ClassificationB24B37/14, B24B37/345, B24B37/245
European ClassificationB24B37/34F, B24B37/24F, B24B37/14
Legal Events
DateCodeEventDescription
May 18, 2001ASAssignment
Owner name: TDK CORPORATION, JAPAN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SASAKI, YOSHITAKA;IIJIMA, ATSUSHI;KUBOTA, TOSHIO;AND OTHERS;REEL/FRAME:011825/0262;SIGNING DATES FROM 20010213 TO 20010308