US20010029158A1 - Polishing apparatus and polishing method, and method of manufacturing semiconductor device and method of manufacturing thin film magnetic head - Google Patents

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.

Description

CROSS REFERENCE TO RELATED APPLICATION
• 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.[0001]
BACKGROUND OF THE INVENTION
• 1. Field of Invention[0002]
• 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.[0003]
• 2. Description of Related Art[0004]
• 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.[0005]
• 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.[0006]
• 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.[0007]
• 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.[0008]
• 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.[0009]
• 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.[0010]
• 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.[0011]
• 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.[0012]
• 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.[0013]
• 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.[0014]
• 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[0015]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.
• 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.[0016]
• FIG. 12 shows CMOS (Complementary Metal Oxide Semiconductor) circuit with a five level interconnect structure as an example of the semiconductor integrated circuit.[0017]
• In the CMOS integrated circuit, an n-[0018]type well region100ais formed in a p-type substrate100 made of such as silicon, for example. A LOCOS (Local Oxidation of Silicon)film101 as an element isolation film is formed on the surface of asubstrate100. An n-type MOS transistor107 comprises a pair of n-type impurity regions103 and104 as a source or a drain and agate electrode106 formed on the surface of thesubstrate100 between theimpurity regions103 and104 with agate oxide film105 in between. A p-type MOS transistor107acomprises p-type impurity regions103aand104aformed in thewell region100aand agate electrode106 formed on the surface of thewell region100abetween theimpurity regions103aand104awith thegate oxide film105 in between. Thegate electrode106 is made of polycrystal silicon film to which impurities are added, and has gate side walls (side walls)106aon its side surfaces. The first tofifth wiring layers109ato109emade of copper (Cu) or aluminium-copper alloy (AlCu) are stacked on theMOS transistors107 and107awith LTO (Low Temperature Oxidation) film 0.2 μm thick, for example, and interlayerinsulating films108ato108f, each 0.8 μm thick and made of BPSG (Boro-Phospho-Silicate Glass), in between. Thewiring layers109ato109eare electrically connected through via-plug110 made of tungsten (W) or the like provided in the interlayerinsulating films108ato108e.
• 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[0019]interlayer insulating films108ato108eis formed after themetallic wiring layers109ato109eare 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 theinterlayer insulating films108ato108eand then metal such as tungsten is deposited on the surface of the substrate including the contact hole by CVD (Chemical Vapor Deposition).
• 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[0020]magnetic head200 comprises a reproducinghead200A and arecording head200B.
• The reproducing[0021]head200A comprises amagnetoresistive film205 made of permalloy (NiFe alloy), for example, formed on asubstrate201 made of altic (alumina titanium carbide; Al₂O₃-TiC), for example, with an undercoatinglayer202 made of alumina (aluminum oxide; Al₂O₃), for example, abottom shield layer203 made of ferrous aluminum silicide (FeAlSi), for example, and a shield gap layer204 made of aluminum oxide (Al₂O₃, referred to as alumina in the followings), for example, in between in this order. Alead electrode layer205ais also formed on the shield gap layer204 and is electrically connected to themagnetoresistive film205. Ashield gap layer106 made of alumina, for example, is stacked on themagnetoresistive film205 and thelead electrode layer205a. In other words, themagnetoresistive film205 and thelead electrode layer205aare buried between the shield gap layers204 and206.
• The[0022]recording head200B comprises atop pole209 formed on the reproducinghead200A with abottom pole207 which also works as a top shield layer for the magnetoresistive film205 (referred to as bottom pole in the followings) and awrite gap layer208 in between. Thetop pole209 is divided into two parts: apole tip209awhich determines the track width and a topmagnetic layer209bwhich works as a yoke. An insulatinglayer210 made of alumina is formed on thebottom pole208. The surface of the insulatinglayer210 is planarized to form the same surface as the surface of thepole tip209a. Thin film coils211 and212 are stacked on the insulatinglayer210, and are covered with insulatinglayers213 and214. The topmagnetic layer209bis formed on thepole tip209aand the insulatinglayers213 and214. The topmagnetic layer209bis covered with anovercoat layer215. In therecording head200B, thebottom pole207 facing thetop pole209 has a trim structure in which part of the surface is processed to be protruded.
• In the reproducing[0023]head200A of such a composite thin film magnetic head, the characteristic of the magnetoresistive element largely depends on the surface of thebottom shield layer203. Therefore, in general, thebottom shield layer203 is planarized before these elements are formed. Similarly, the surface of thebottom pole208 is planarized before thewrite gap layer208 is formed in order to improve the performance of therecording head200B. Further, in therecording head200B, thetop pole209 is divided into thetop pole tip209aand the topmagnetic layer209bin order to form a narrow track. The insulatinglayer210 is planarized after thepole tip209ais formed.
• 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.[0024]
• 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)[0025]301 pasted on aplaten300. 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 awafer holder302 and theabrasive pad301 while theplaten300 and thewafer holder302 to which a wafer is attached are rotated.
• In such a polishing apparatus, materials with a large frictional drag or materials with a small frictional drag is used as the[0026]abrasive pad301 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 theabrasive pad301 depending on its usage. Further, planarization of the wafer is performed by changing the rotation frequency of thewafer holder302 and theplaten300 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.
• 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.[0027]
• 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.[0028]
• FIG. 15A shows a state in which an[0029]interlayer insulating film402 about2 mm thick made of silicon oxide film (SiO₂) is formed on a plurality ofmetallic wiring patterns401 with a film thickness of 0.7 μm which are formed on afield oxide film400 formed on a silicon substrate. Theinterlayer insulating film402 hasprotrusions402aover a region where the minutemetallic wiring patterns401 are aggregated. FIG. 15B shows a state after planarizing the surface of theinterlayer insulating film402 by the CMP apparatus shown in FIG. 12.
• As seen from FIGS. 15A and 15B, when a wafer including part in which the minute[0030]metallic wiring patterns401 are aggregated (dense region) and other part in which themetallic wiring patterns401 are not aggregated (empty region) is planarized by the CMP apparatus, the region of theprotrusions402awhere themetallic wiring patterns401 are aggregated is completely planarized. However, the areas between two dense regions where the wiringmetallic patterns401 are densely formed do not have high flatness.
• 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.[0031]
• 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.[0032]
• 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.[0033]
• Next, specific problems in the manufacturing process of a thin film magnetic head will be described with reference to FIGS. 16A to[0034]16C. The figures show the thin film magnetic head viewed from the ABS side. As shown in FIG. 16A, an insulatinglayer501 about 3 to 5 μm thick made of alumina is deposited on asubstrate500 made of altic by sputtering, for example. Next, abottom shield layer502 about 2 to 3 μm thick for the reproducing head made of a magnetic material such as permalloy (NiFe) is formed on the insulatinglayer501 by plating, for example. Then an insulatinglayer503 about 3 to 4 μm thick made of alumina is formed on thebottom shield layer502. The insulatinglayer503 hasprotrusions503aover thebottom shield layer502.
• FIG. 16B shows a state after the surface of the insulating[0035]layer503 is planarized by a polishing apparatus. In such a thin film magnetic head, it is necessary to polish the surface of the insulatinglayer503 to reach thebottom shield layer502 so as to make thebottom shield layer502 exposed in the surface of the insulatinglayer503. As a result, there are steps between the insulatinglayer503 and thebottom shield layer502 so that either the insulatinglayer503 or thebottom shield layer502 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.
• As shown in FIG. 16C, after a bottom[0036]shield gap film504, amagnetoresistive film505 and itslead electrode layer506, a topshield gap film507 and a top shield-cum-bottom pole508 are formed in a thickness of about 2 to 4 μm, another insulatinglayer509 made of alumina is formed in a thickness of 3 to 5 μm, and then the surface of the insulatinglayer509 is polished by the polishing apparatus. The recesses are also formed at this time. Further, after awrite gap film510 is formed in a thickness of 0.2 to 0.3 μm, apole tip511 is formed in a thickness of 2 to 3 μm. Again, an insulatinglayer512 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.
• 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.[0037]
• 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.[0038]
• 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.[0039]
SUMMARY OF THE INVENTION
• 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.[0040]
• 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.[0041]
• 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.[0042]
• A polishing apparatus of the invention comprises a plurality of polishing portions for performing polishing processing of different degrees on one subject of polishing.[0043]
• 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.[0044]
• 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.[0045]
• 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.[0046]
• 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.[0047]
• 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.[0048]
• 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.[0049]
• 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.[0050]
• 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.[0051]
• 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.[0052]
• 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.[0053]
• 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.[0054]
• 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.[0055]
• 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.[0056]
• 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.[0057]
• 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.[0058]
• 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.[0059]
• 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.[0060]
• 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.[0061]
• In the polishing method of the invention, the polishing steps may be performed in a plurality of polishing portions included in one pedestal.[0062]
• 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.[0063]
• 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.[0064]
• Other and further objects, features and advantages of the invention will appear more fully from the following description.[0065]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view showing a configuration of a polishing apparatus according to a first embodiment of the invention.[0066]
• FIG. 2 is a figure showing a cross sectional configuration of the polishing portion taken along the line II-II in FIG. 1.[0067]
• FIG. 3 is a cross section showing a configuration of an abrasive pad in the polishing apparatus shown in FIG. 1.[0068]
• FIG. 4 is a perspective view showing a configuration of the polishing apparatus according to a second embodiment of the invention.[0069]
• FIGS. 5A and 5B are cross sections for describing a planarization process of a semiconductor integrated circuit by the polishing apparatus of the invention.[0070]
• FIGS. 6A, 6B and[0071]6C are cross sections for describing a planarization process of a thin film magnetic head by the polishing apparatus of the invention.
• FIG. 7 is a characteristic diagram for describing the polishing result using the polishing apparatus of the related art.[0072]
• 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.[0073]
• FIG. 9 is a plan view for describing the measuring point of the wafer in the characteristic diagrams shown in FIGS. 8A and 8B.[0074]
• FIG. 10 is a perspective view for describing an example of grinder used in the polishing apparatus of the invention.[0075]
• FIG. 11 is a plan view for describing a schematic configuration of the apparatus according to still another embodiment of the invention.[0076]
• FIG. 12 is a cross section of a CMOS circuit as an example to which a planarization process by the polishing apparatus is applied.[0077]
• 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.[0078]
• FIG. 13B is a cross section of the thin film magnetic head shown in FIG. 13A viewed from the ABS side.[0079]
• FIG. 14 is a perspective view showing a configuration of a polishing apparatus of the related art.[0080]
• 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.[0081]
• FIGS. 16A, 16B and[0082]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
• Preferred embodiments of the invention will be described in the followings with reference to corresponding figures.[0083]
• [First Embodiment][0084]
• FIG. 1 shows a configuration of a[0085]polishing apparatus1 according to a first embodiment of the invention. The polishingapparatus1 is for polishing a subject of polishing such as the surfaces of wafers and comprises apedestal10. A plurality of (three, for example, in this embodiment) polishing portions11A to11C, and acleaning portion11D are provided on thepedestal10. The polishing portions11A to11C and thecleaning portion11D compriseplatens12ato12drespectively. Theplatens12ato12dare placed on the surface of thepedestal10 in a rotatable state. Theplatens12ato12dare coupled to a rotating device (not shown in figure) provided under thepedestal10 through openings (not shown in figure) provided in thepedestal10. Theplatens12ato12dare made to rotate with a predetermined speed in a counterclockwise direction when viewed from the above.
• Four wafer holders (heads)[0086]14 are placed on thepedestal10 facing theplatens12ato12d. Thewafer holders14 comprise aholder14a(not shown in FIG. 1, see FIG. 2) for holding wafers. Thewafer holder14ais 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 shaft14b. The surfaces of theplatens12ato12din the polishing portions11A to11C and thecleaning portion11D respectively have different roughness and hardness from one another. The wafer to be polished, together with thewafer holder14a, is moved to a position facing theplatens12ato12dof the polishing portions11A to11C and thecleaning portion11D in this order to be polished and cleaned to a different degree.
• At least part of the polishing surface of the[0087]platen12a, 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.
• FIG. 2 shows an example of a cross sectional configuration of the polishing portion[0088]11A shown in FIG. 1 taken along the line II-II. In FIG. 2, theholder14aof thewafer holders14 is formed of porous chuck. A wafer W is adsorbed and held by theholder14athrough thecavity14cprovided in thewafer holder14 being evacuated in the direction shown by an arrow a in the figure. In the polishing portion11A, alubricant16 is supplied from a nozzle15. Examples of the lubricants are pure water, oil, isopropyl alcohol, alumina slurry, silica slurry and the like.
• In the embodiment, first, polishing (roughing) of the wafer W is performed by the[0089]platen12ain the polishing portion11A while supplyinglubricator16 from the nozzle15. 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 portion11A, theplaten12ais 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 portion11A corresponds to the “first polishing portion” of the invention.
• The abrasive pad[0090]13bwith a single-layered structure made of, for example, a hard polyurethane form is pasted on the surface of the platen12bin the polishingportion11B. Polishing is performed by the abrasive pad13busing 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 polishingportion11B 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 portion11 A by the abrasive pad13b. The polishingportion11B 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 polishingportion11B 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.
• The[0091]abrasive pad13cwith a structure of a plurality of (two, for example) layers is pasted on the surface of theplaten12cin the polishingportion11 C. FIG. 3 shows an example of a cross sectional configuration of theabrasive pad13cincluding theplaten12c.
• The[0092]abrasive pad13chas a two-layered structure of asurface layer13c₁and abottom layer13c₂. Thesurface layer13c₁is formed of a porous polyurethane form, for example, while thebottom layer13c₂is formed of an elastic material such as polyurethane or a gum rubber, which is softer than thesurface layer13c₁, or of a hard material such as ceramic or plastic. The polishingportion11C performs finishing through lightly polishing the surface of the wafer by theabrasive pad13c. The polishingportion11C corresponds to an embodiment of the “second polishing portion” of the invention. Also, the same abrasive liquid including slurry as in the polishing11B is supplied from the nozzle15 to theabrasive pad13c.
• A[0093]cleaning pad13dwith a single-layered structure including a brush with long pile is pasted on the surface of theplaten12din thecleaning portion11D. The cleaningportion11D completely removes (cleans) the contamination left by the micro scratches or slurry generated in the prior process by thecleaning pad13dusing pure water or alcohol as the lubricant. The cleaningportion11D 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.
• Next, operation of the[0094]polishing apparatus1 will be described.
• In polishing portions[0095]11A to11C, and the cleaning portion1ID of thepolishing apparatus1, theplatens12ato12dand thewafer holder14 for holding the wafer W rotates in the reverse direction of each other. The wafer W as a subject of polishing, together with thewafer holder14a, is moved to a position facing theplatens12atol2cof the polishing portions11A to11C and to theplaten12dof thecleaning portion11D in this order so as to be polished and cleaned to a different degree.
• First, in the polishing portion[0096]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 theplaten12amade of a hard grinder. In this case, the polishing surface of the wafer W exhibits no pattern dependence since the polishing surface is hard.
• The wafer W to which roughing has been performed in the polishing portion[0097]11A is then moved to the polishingportion11B. In the polishingportion11B, scratches and polishing distortion slightly generated in the wafer by theplaten12aare removed (medium polishing) by the hard abrasive pad13bwith 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.
• The wafer W to which the medium polishing has been performed in the polishing[0098]portion11B is then moved to the polishingportion11C. In the polishingportion11C, finishing is performed by theabrasive pad13cwith a two-layered structure. In theabrasive pad13c, thesurface layer13c₁made of a hard polyurethane form or the like is supported by thebottom layer13c₂made of a softer material than thesurface layer13c₁. 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.
• In the polishing[0099]portion11C, the wafer W to which finishing has been performed is then moved to thecleaning portion11D. In thecleaning portion11D, 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 thecleaning pad13d. Thereby, the final finishing is performed and a series of the planarization process is completed.
• As described, the polishing[0100]apparatus1 according to the embodiment comprises three polishing portions11A to11C. Roughing, medium polishing and finishing of the wafer W are performed in the polishing portions11A to11C respectively to planarize the wafer W. In other words, the wafer W is roughly polished by theplaten12amade of rough and hard grinder in the polishing portion11 A, and then is medium-polished by the relatively hard abrasive pad13bin the polishingportion11B. 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 softabrasive pad13cin the polishingportion11C. At last, micro cracks and scratches are completely removed by thesoft cleaning pad13dwith long pile in thecleaning portion11D.
• 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.[0101]
• Further, in the embodiment, four[0102]wafer holders14 sequentially move to the polishing portions11A to11C and thecleaning portion11D 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 portions11A to11C and thecleaning portion11D. When the processing period of the wafer does not meet mutually in each portion, the wafer may be made stood by in the polishing portions11A to11C and thecleaning portion11D.
• Second Embodiment][0103]
• FIG. 4 shows a configuration of a[0104]polishing apparatus2 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.
• The[0105]polishing apparatus2 comprises two polishingportions21A and21B, and acleaning portion21C. The polishingportions21A,21B and the cleaningportion21C compriseplatens22ato22crespectively, and wafer holders (heads)24 are placed facing each of theplatens22aand22c. The surfaces of theplatens22ato22chave different roughness from one another. The wafer W, together with thewafer holder24, is moved to the polishingportions21A,21B and to thecleaning portion21C in this order to be polished and cleaned to a different degree.
• A hard polishing[0106]abrasive pad23awith a single-layered structure made of a hard resin such as a polyurethane form is pasted on the surface of theplaten22ain the polishing portion21A. The polishing liquid including slurry is supplied from a nozzle (not shown in figure) to theabrasive pad23a. Examples of the slurry are alumina, silica and a mixture of both. In the polishing portion21A, theplaten22amay also be formed of a grinder and perform polishing using the lubricant as in the first embodiment. The polishing portion21A 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 theplaten22a. In the embodiment, the polishing portion21A corresponds to another embodiment of the “first polishing portion” of the invention. The polishing surface of theplaten22ais the hardabrasive pad23aso 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 portion21A 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 polishingportion11B according to the first embodiment.
• An[0107]abrasive pad23bwith a two-layered structure is pasted on the surface of theplaten22bin the polishingportion21B. Theabrasive pad23bhas the same configuration as that of theabrasive pad13cof the first embodiment, for example. The polishingportion21B performs finishing through removing micro scratches and polishing distortion slightly generated in the polishing portion21A by lightly polishing the surface of the wafer by theabrasive pad23b. The polishingportion21B corresponds to another embodiment of the “second polishing portion” of the invention. The polishing liquid including slurry is supplied from a nozzle to theabrasive pad23b. 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 portion21A is precisely controlled in the polishingportion21B and scratches on the surface of the magnetic layer made of permalloy are removed while recesses being 0.05 μm or less.
• A[0108]cleaning pad23chaving the same configuration as that of the cleaning pad11dof the first embodiment, for example, is pasted on the surface of theplaten22cin thecleaning portion21C. The cleaningportion21C completely removes (cleans) the contamination left by the micro scratches or slurry generated in the prior process by thecleaning pad23cusing pure water or alcohol as the lubricant. The cleaningportion21C corresponds to another embodiment of the “cleaning portion” of the invention.
• First, in the polishing portion[0109]21A of thepolishing apparatus2 according to the embodiment, roughing is performed by theabrasive pad23aformed 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 portion21A is moved to the polishingportion21B.
• In the polishing[0110]portion21B, finishing is performed through removing micro scratches and polishing distortion slightly generated in the wafer W in the polishing portion21A by theabrasive pad23bwith 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 portion21A until right before the shield pole or the recording pole made of permalloy or the like is exposed in the surface of the wafer.
• Finally, when finishing is performed to the wafer W in the polishing[0111]portion21B, in thecleaning portion21C, the contamination left by the micro scratches or slurry generated in the prior process is completely cleaned by thecleaning pad23c.
• As described, in the[0112]polishing apparatus2 according to the embodiment, roughing and finishing are performed in the two polishingportions21A and21B by theabrasive pads23aand23bhaving different roughness and hardness from each other. Further, cleaning is performed in thecleaning portion21C. 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.
• 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[0113]apparatuses1 and2.
• 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[0114]interlayer insulating film32 about 2 μm thick made of silicon oxide film (SiO₂) is formed on a plurality ofmetallic wiring patterns31 with a thickness of 0.7 μm, for example, on thefield oxide film30 which is formed on a silicon substrate. Theinterlayer insulating film32 hasprotrusions32aover the region where minutemetallic wiring patterns31 are aggregated. FIG. 5B shows a state after the surface is planarized by the above-mentionedpolishing apparatuses1 or2.
• As evident from the figure, in the embodiment, not only the[0115]protrusions32aover the aggregatedmetallic wiring patterns31 but areas between two regions where themetallic wiring patterns31 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.
• Next, FIGS. 6A to[0116]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 insulatinglayer41 about 3 to 5 μm thick made of alumina is formed on asubstrate40 made of altic by sputtering, for example. Then abottom shield layer42 about 2 to 3 μm thick for a reproducing head made of magnetic materials such as permalloy (NiFe) is formed on the insulatinglayer41 by plating, for example. An insulatinglayer43 about 3 to 4 μm thick made of alumina is formed on thebottom shield layer42. The insulatinglayer43 hasprotrusions43aover thebottom shield layer42.
• FIG. 6B shows a state after the surface of the insulating[0117]layer43 is planarized by the above-mentionedpolishing apparatuses1 or2. In such a thin film magnetic head, the surface is polished to reach thebottom shield layer42 so that thebottom shield layer42 is exposed in the surface of the insulatinglayer43. In the related art, as described above, there are steps between the insulatinglayer43 and thebottom shield layer42 so that either the insulatinglayer43 or thebottom shield layer42 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 insulatinglayer43 and thebottom shield layer42, and polishing speed and the thickness of the remained film of both layers are controlled more precisely.
• In the embodiment, then, as shown in FIG. 6C, a bottom shield gap film[0118]44, amagnetoresistive film45, a lead layer (lead)46 connected to themagnetoresistive film45, a top shield gap film47 and a top shield-cum-bottom pole48 are formed in a thickness of about 2 to 4 μm. Then, an insulatinglayer49 about 3 to 5 μm thick made of alumina is formed and the surface of the insulatinglayer49 is polished by the polishingapparatuses1 or2. In the embodiment, recesses are rarely formed also at this time. Further, after awrite gap film50 in a thickness of 0.2 to 0.3 μm is formed, apole tip51 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)51b, 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.
• 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.[0119]
EXAMPLE
• 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 3000[0120]^thvitrified 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 ofIC 1000 andSuba 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.
• In contrast, FIGS. 8A and 8B show the result of performing planarization by the polishing[0121]apparatus1 according to the embodiment. In the FIGS. 8A and 8B, numerals from1 to9 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 amagnetic layer 3 μm thick made of permalloy and the insulating film was planarized by the polishingapparatus1. 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.
• 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[0122]apparatus1 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.
• 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.[0123]
• 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[0124]wafer holder14 in the above-mentioned embodiments, it may be performed by rotating thepedestal1 instead.
• Although disk-shaped grinders are used as the grinders for performing roughing in the above-mentioned embodiments, a ring-shaped (or cup-shaped)[0125]grinder60 may be used for polishing the surface of the wafer W as shown in FIG. 10. At this time, thegrinder60 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.
• 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.[0126]
• 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[0127]polishing apparatus70 comprising three polishingportions71A to71C, and acleaning apparatus80 comprising twocleaning portions81A,81B with different degrees of cleaning and a dryingportion81C are connected by anunderwater elevator90. The polishingportions71A to71C in the polishingapparatus70 are composed of aplaten72 and awaferholder73 and correspond to the polishing portions11A to11C of the first embodiment. In the polishingapparatus70, the wafer W sent in through aloader74 is moved to each of the polishingportions71A to71C by an arm robot75 to receive roughing, medium polishing and finishing. The wafer to which finishing has been performed is moved in a wet state to thecleaning apparatus80 by theunderwater elevator90. In the cleaningportion80, the wafer W is roughly cleaned in the cleaning portion81A, finely cleaned by the cleaningportion81B and spin-dried in the dryingportion81C in order. At last, the wafer W is taken out from thecleaning apparatus80 through anunloader82.
• 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.[0128]
• 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.[0129]
• 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.[0130]
• 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.[0131]

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.

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