JP2000042914A - Grinding device and method and manufacture of semiconductor device and thin film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding device capable of accurately performing a flattening process, in accordance with the finishing of a semiconductor device or a thin film magnetic head, etc. SOLUTION: A grinding device 1 is equipped with plural, e.g. three, grinding parts 11A-11C, and a cleaning part 11D. At first in the grinding part 11A, rough grinding is made by a surface plate 12a composed of a hard grinding wheel, and at that time, the pattern dependency of a wafer is not seen on a grinding surface because of the hard grinding surface of the surface plate 12a. Next in the grinding part 11B, a scratch or abrasive distorsion, slightly occurring in the wafer in the surface plate 12a, is removed (half-ground) by a hard grinding pad 13b having single layer structure, and successively grinding is finished by a grinding pad 13c having two layer structure in the grinding part 11C. Finally in the cleaning part 11D, a microscratch occurring in former processes or a contaminant by a slurry are completely washed away by a cleaning pad 13d in the cleaning part 11D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polishing apparatus and a polishing method for flattening, for example, a thin film magnetic head and a semiconductor integrated circuit, and a method of manufacturing a semiconductor device and a thin film magnetic head.

[0002]

2. Description of the Related Art In a process of manufacturing a semiconductor integrated circuit using silicon or the like, it is necessary to finely form a metal wiring in order to miniaturize a device and improve element performance. Specifically, it is necessary to form the pattern with sub-micron dimensions and to form such a pattern with multiple layers.

In such a multilayer wiring structure, an interlayer insulating film made of a silicon oxide film or the like is formed between metal wiring layers. In such a structure, a step having a thickness of about 0.5 μm to 0.7 μm occurs due to the metal wiring. Therefore, when further forming a metal wiring thereon, an interlayer insulating layer is formed before forming the metal wiring. The film needs to be planarized.

[0004] A similar problem also occurs in the manufacturing process of a thin film magnetic head. In recent years, as the areal recording density of a hard disk drive has been improved, the performance of a thin-film magnetic head has been required to be improved. A composite thin-film including a recording head having an inductive magnetic transducer and a reproducing head having a magnetoresistive element Magnetic heads are widely used. In addition, an anisotropic magnetoresistance (Anis
There are an AMR element using the (otropic magneto-resistive) effect, a GMR element using the giant magneto-resistive (Giant Magneto Resistive) effect, and the like.

In such a composite type thin film magnetic head, it is necessary to improve the performance of both the recording head and the reproducing head. For this purpose, for example, in addition to selection of a material constituting each part, fine processing of a track width and the like are being advanced.

For example, in order to increase the recording density of a recording head, it is necessary to form its magnetic pole portion finely. For this purpose, submicron processing using semiconductor processing technology is performed. Then, as the magnetic pole portion is miniaturized, in order to accurately write information, it is necessary that at least one magnetic pole has a thickness of about 2.5 μm to 3.5 μm. When configuring such a magnetic pole, the lower layer needs to be flattened.

[0007] A reproducing head is also required to have the same submicron dimension as the track width of the magnetoresistive film. Usually, this magnetoresistive film has a thickness of 2.0 μm to 3.0 μm.
It is formed on a shield magnetic film having a thickness of about m through a shield gap layer. Therefore, when the magnetoresistive film is formed, the lower layer needs to be flattened.

[0008] The performance of the recording head is based on an air bearing surface (AirBearing Surface: A) called a slow height.
Depending on the distance from BS), this slow height is A
It is determined by the amount of polishing at the time of BS processing. The performance of the read head also depends on the distance from the ABS, which is called the MR height, and this MR height is also determined by the amount of polishing at the time of ABS processing.

As described above, with the improvement of the performance of the semiconductor integrated circuit and the thin film magnetic head, the fine processing technology and the flattening technology are the most important process technologies. Of these, since the fine processing process is performed with high precision only after the planarization process is performed accurately, the planarization process needs to be performed accurately in order to improve the performance of the semiconductor device and the thin film head device.

Meanwhile, as a planarization technique, CMP (Chemical and Mechanical) using a slurry (abrasive) is used.
Polishing: MP (Mechanical Polishing), a method of polishing using oil etc. as a lubricant on a surface plate embedded with fine diamond particles studded and embedded.
Mechanical polishing) method.

However, in the CMP method, there are various problems because the polishing pad has a polishing characteristic of following the wafer pattern. On the other hand, in the MP method,
Scratch easily occurs on the surface of the wafer. In order to suppress the occurrence of scratches, diamond having a fine grain size may be used, but in that case, there is a problem that the polishing rate is reduced.

[0012] In the polishing apparatus according to these methods,
Each of them has one platen (platen) and has a structure for polishing the surface of a wafer. On the other hand, some polishing machines have two surface plates (for example, AVANTE472, IPEC P
LANER). However, this polishing device, on one of the platens,
A two-layer polishing pad made of a relatively soft material (for example, RODRL Nitta IC1000 and suba400 or 800), and a cleaning pad with a soft brush with long limbs on the other surface plate. Yes, after polishing once using a polishing pad, the slurry attached by the cleaning pad is removed. Therefore, in this polishing apparatus, as in the case of the polishing apparatus having one platen, various problems occur in the controllability of the polishing amount due to the pattern dependence in the wafer.

Hereinafter, a specific problem in the case where planarization is performed using these polishing apparatuses will be described. Before that, the structure of a semiconductor integrated circuit and a thin film magnetic head to which the planarization process is applied will be described. .

First, FIG. 12 shows a CMOS (Complementary Metal) having a five-layer wiring structure as an example of a semiconductor integrated circuit.
Oxide Semiconductor) circuit.

In this CMOS integrated circuit, an n-type well region 100 is formed in a p-type substrate 100 such as silicon.
a is formed. On the surface of the substrate 100, a LOCOS (Local Oxidation of Silicon) film 101 is formed as an element isolation film. n-type MOS transistor 10
Reference numeral 7 denotes a pair of n-type impurity regions 103 and 104 serving as source or drain regions, and these impurity regions 103 and 104.
The gate electrode 106 is formed on the surface of the substrate 100 between the gate electrodes 104 via the gate oxide film 105. The p-type MOS transistor 107a is connected to the well region 1
P type impurity regions 103a, 103a
4a and a gate electrode 106 formed on the surface of the well region 100a between the impurity regions 103a and 104a with a gate oxide film 105 interposed therebetween. The gate electrode 106 is formed of a polycrystalline silicon film to which an impurity is added, and has a gate side wall (side wall) 106a on a side surface thereof. On such MOS transistors 107 and 107a, for example, a film thickness of 0.2 μm
LTO (Low Temperature Oxidation) film and thickness 0.8
The first to fifth wiring layers 109a to 109e made of copper (Cu) or aluminum / copper alloy (AlCu) are interposed via interlayer insulating films 108a to 108f made of BPSG (Boro-Phospho-Silicate Glass) of μm, respectively. It is laminated. The interlayer insulating film 1 is between the wiring layers 109a to 109e.
The electrodes are electrically connected via via plugs 110 made of tungsten (W) or the like provided at 08a to 108e.

In such a CMOS circuit manufacturing process, planarization is performed in each layer by using a metal wiring layer 109.
After forming the layers a to 109e, the interlayer insulating films 108a to 108e are formed.
8f is formed, and this is performed when polishing the protrusions of the interlayer insulating film on the wiring layers 109a to 109e. Thereafter, connection holes (contact holes and via holes) are formed in the interlayer insulating films 108a to 108e, and CVD (Chemical V
After a metal such as tungsten is deposited on the surface of the substrate including the connection holes by the (apor Deposition: chemical vapor deposition) method,
Flattening is also performed when removing metal adhered to the substrate surface other than the connection holes.

FIGS. 13A and 13B show a cross-sectional structure of a composite thin film magnetic head as an example of a conventional thin film magnetic head. Note that in FIG.
Shows a cross section perpendicular to the track surface, and (B) shows a cross section of the magnetic pole portion parallel to the track surface. The magnetic head 200 includes a reproducing head 200A and a recording head 200B.
And

The reproducing head 200A is made of, for example, Altic (alumina titanium carbide, Al ₂ O ₃ .TiC).
A base layer 202 made of, for example, alumina (aluminum oxide, Al ₂ O ₃ ) on a substrate 201 made of
For example, permalloy (NiFe alloy) through a lower shield layer 203 formed of, for example, iron aluminum silicide (FeAlSi), for example, a shield gap layer 204 formed of aluminum oxide (Al ₂ O ₃ , hereinafter, referred to as alumina). The pattern of the magnetoresistive film 205 is formed. A lead electrode layer (lead) 205a is also formed on the shield gap layer 204, and the lead electrode layer 205a is electrically connected to the magnetoresistive film 205. On the magnetoresistive film 205 and the extraction electrode layer 205a, a shield gap layer 106 made of, for example, alumina is laminated. That is, the magnetoresistive film 205 and the extraction electrode layer 205a are formed by the shield gap layers 204 and 20.
It is buried between six.

The recording head 200B includes the reproducing head 2
A lower magnetic pole (hereinafter, referred to as a lower magnetic pole) 20 also serving as an upper shield layer for the magnetoresistive film 205
7. An upper magnetic pole (upper pole) 209 is formed via a recording gap layer 208. The upper magnetic pole 209 is
Magnetic pole tip (pole tip) 20 that defines track width
9a and an upper magnetic layer 209b also serving as a yoke. An insulating layer 210 made of alumina is formed on the lower magnetic pole 208, and the surface of the insulating layer 210 is flattened so as to form the same surface as the surface of the magnetic pole tip 209a. On the insulating layer 210, the thin film coil 211,
212 are stacked. These thin-film coils 211,
12 is covered with insulating layers 213 and 214. An upper magnetic layer 209b is formed on the pole tip 209a and the insulating layers 213 and 214. Upper magnetic layer 209b
Are covered by the overcoat layer 215. In addition,
In the recording head 200B, the lower magnetic pole 207 facing the upper magnetic pole 209 has a trim (Trim) structure in which the surface portion is partially protruded.

In such a composite type thin film magnetic head, in the reproducing head 200A, the surface of the lower shield layer 203 greatly affects the characteristics of the magnetoresistive element. Therefore, the lower shield layer 203 is generally planarized in a process before forming these elements.
Similarly, in order to improve the performance of the recording head 200B, the surface of the lower magnetic pole 208 is flattened in a step before forming the recording gap layer 208. Further, in the recording head 200B, in order to form a narrow track, the upper magnetic pole 209 is divided into a magnetic pole tip 209a and an upper magnetic layer 209b. After the magnetic pole tip 209a is formed, the insulating layer 210 is flattened. Is made.

In any case, in the case of the thin-film magnetic head, the magnetic material and the insulating material, the metal material for the coil, and the like are mostly exposed on the surface by flattening. Therefore, in the planarization process using the conventional polishing apparatus,
Simultaneous polishing of a magnetic material and an insulating material or a metal material has caused important problems such as good or bad flatness, generation of a scratch, and generation of a recess (dent) between the insulating film and the metal layer.

FIG. 14 shows, as an example of a conventional CMP apparatus, the configuration of a platen (platen) and a wafer holder (head) of a polishing section. This CMP device
A polishing pad (polishing cloth) 301 is stuck on the surface plate 300, and while the surface plate 300 and the wafer holder 302 on which the wafer is mounted are rotated, a slurry having a certain particle diameter is supplied to the wafer holder 302. And polishing pad 30
1 and polish it, polishing the irregularities on the surface of the wafer,
This is to flatten the surface of the wafer.

By the way, in such a polishing apparatus, a material having a large or small frictional resistance is used as the polishing pad 301 according to a desired polishing rate and a desired polishing amount. Further, as the polishing pad 301, a two-layer pad in which a hard pad and a soft pad are bonded to each other, or a single-layer pad using a hard pad or a soft material is used depending on the application. Further, the number of rotations of the wafer holder 302 and the platen 300 is changed, and the rotation direction is set to a forward direction or a reverse direction, thereby flattening the wafer. In addition, the amount of polishing and the polishing rate of the wafer and the amount of polishing within the wafer are made uniform in consideration of the type of the material of the slurry, the size of the particle size, and the like.

However, in such a method, the polishing accuracy is limited, as will be specifically described below. In particular, the pattern shape in the wafer is an important factor in determining the uniformity of planarization. Had become.

First, referring to FIGS. 15A and 15B,
A problem in forming a metal wiring in a conventional semiconductor integrated circuit will be described.

FIG. 15A shows a plurality of metal wiring patterns 401 having a thickness of 0.7 μm on a field oxide film 400 formed on a silicon substrate, and an interlayer made of a silicon oxide film (SiO ₂ ). This shows a state where the insulating film 402 is formed with a thickness of about 2 μm. In a region where the fine metal wiring patterns 401 are gathered, the interlayer insulating film 40
2, a convex portion 402a is formed. From this state, the interlayer insulating film 4 is formed by a CMP apparatus as shown in FIG.
FIG. 15 shows a state where the surface of No. 02 is flattened.
(B).

The fine metal wiring pattern 401
Is flattened by a CMP apparatus having a portion (dense region) where a large number of condensates are gathered and a portion (sparse region) where the portion is not so large, a portion where the metal wiring patterns 401 of the convex portions 402 a are completely flat. However, the accuracy of flatness between the dense regions of the metal wiring pattern 401 is not good.

That is, in such a flattening process, the shape after the flattening differs depending on the pattern shape of the metal wiring in the wafer and the arrangement of the aggregate portion of the pattern. Generally, when polishing a dense area of a fine pattern and an isolated pattern of a fine pattern or a large pattern, the contact area between the polishing pad and the convex portion of the pattern in the wafer is different, and the polishing rate and the flattening are correspondingly different. Shape is different. The fine isolated pattern has a higher polishing rate than the aggregate of large patterns. Therefore, the thickness of the interlayer insulating film in that portion is different, and when forming a contact hole or the like on the interlayer insulating film, over-etching is required according to the thickness of the thickest interlayer insulating film.

For example, 0.5 μm, 0.3 μm, 0.2
RIE (Reacti)
In the case of forming by dry etching such as ve ion etching (reactive ion etching), a lot of over etching is required. As a result, the ohmic contact resistance between the contact hole and the like and the electrode wiring is increased, which hinders the performance of many device characteristics, which is a factor of deteriorating the yield. Also, as the number of layers increases, such as four or five layers of multilayer wiring, when a region having a portion where many fine metal wiring patterns are gathered and a portion having a portion other than that are flattened by CMP as described above, In addition, the portion where the metal wiring patterns are gathered is accurately flattened, but the flatness accuracy between the gathered portions of the metal wiring patterns is not good.

As described above, in the conventional CMP apparatus, although excellent flatness can be obtained locally, there is a problem that sufficient flatness cannot be obtained globally. For this reason, in the conventional semiconductor integrated circuit manufacturing process, when the line width of the metal wiring pattern is small, in a region having poor flatness, a wiring layer thereabove is broken or a defect due to electromigration occurs. There was a problem.

Next, referring to FIGS. 16A to 16C,
Specific problems in the manufacturing process of the thin-film magnetic head will be described. This figure shows the thin film magnetic head as viewed from the ABS side. FIG. 3A shows that an insulating layer 501 made of alumina is deposited on an AlTiC substrate 500 by, for example, a sputtering method to a thickness of about 3 to 5 μm. Next, a lower shield layer 502 for a reproducing head made of a magnetic material such as permalloy (NiFe) is formed on the insulating layer 501 by, for example, plating to a thickness of 2 to 3 μm.
m, and then an insulating layer 503 made of alumina of 3 to 4 μm is formed on the lower shield layer 502. On the lower shield layer 502, a protrusion 503a is formed on the insulating layer 503.

FIG. 2B shows a state in which the surface of the insulating layer 503 is flattened by a polishing apparatus from this state. In such a thin film head, the lower shield layer 50
It is necessary to polish the surface up to the lower shield layer 502 so that 2 is exposed on the surface of the insulating layer 503. As a result, a step is generated between the insulating layer 503 and the lower shield layer 502, and it is inevitable that the insulating layer 503 or the lower shield layer 502 has a recessed structure having a partially concave portion. At this time, the recess value reached 0.15 to 0.3 μm, and sometimes reached 0.4 μm or more.

Thereafter, as shown in FIG. 3C, the lower shield gap film 504, the magnetoresistive film 505, its lead electrode layer 506, and the upper shield gap film 50 are formed.
7. After forming the upper shield layer and lower magnetic pole 508 with a thickness of about 2 to 4 μm, an insulating layer 509 made of alumina is again formed with a thickness of 3 to 5 μm.
09 is polished by a polishing apparatus. Recesses also occur here. Thereafter, the write gap film 510 is
After forming the magnetic pole tip (pole tip) 511 with a thickness of 2 to 3 μm, the insulating layer 512 made of alumina is formed again with a thickness of 3 to 4 μm, and then polished. Again, 0.2-0.4 μm
Recess occurs. Finally, a thin film coil (not shown), an upper magnetic layer (top pole) 513, an overcoat layer (not shown) and the like are formed, and the manufacturing process of the thin film magnetic head is completed.

As described above, in the manufacturing process of the thin-film magnetic head, the situation is slightly different from that of the semiconductor integrated circuit described above. That is, a material to be polished is different, and a plurality of layers having different hardnesses are generally polished. For example, a thin-film magnetic head has a structure in which an insulating layer made of alumina and a thin-film coil made of permalloy (NiFe) or copper (Cu) are exposed together on the surface. Therefore, it is necessary to end the CMP process in consideration of these materials and the polishing rate. In addition, the polishing rate varies depending on the pattern, and it is extremely difficult to control the uniformity of the polishing amount of the entire wafer.

In addition to controlling the polishing amount by CMP, for example, the thickness of the lower shield layer after polishing, the thickness of the upper shield layer, and finally the pole tip (pole tip)
Had to be excellent in uniformity within the wafer. This greatly affects the performance of the thin-film magnetic head, and therefore, it is necessary to accurately control the film thickness.

However, the conventional polishing apparatus cannot realize a CMP process capable of accurately controlling the thickness of an insulating layer made of alumina or the like and a magnetic layer (shield magnetic film or recording magnetic pole) made of permalloy (NiFe) or the like. . This is because, as described above, it is extremely difficult to make the polishing rates of materials having different hardnesses such as an insulating layer such as alumina and a metal such as permalloy the same, so that the lower shield layer and the upper shield layer, and This is because a recess is generated between the insulating layer and the lower shield layer or the upper shield layer when the tip of the magnetic pole is polished. This was one of the factors hindering the performance of the thin-film magnetic head.

The present invention has been made in view of such a problem, and a first object of the present invention is to perform a flattening process with high precision in response to miniaturization of devices such as semiconductor devices and thin-film magnetic heads. It is an object of the present invention to provide a polishing apparatus and a polishing method that can perform the polishing.

A second object of the present invention is to provide a method of manufacturing a semiconductor device capable of performing a flattening process with high precision in response to miniaturization.

A third object of the present invention is to provide a method of manufacturing a thin film magnetic head capable of performing a flattening process with high precision in response to miniaturization.

[0040]

SUMMARY OF THE INVENTION A polishing apparatus according to the present invention is a polishing apparatus for polishing and flattening an object to be polished, and performs different degrees of polishing processing on one object to be polished. It has a configuration provided with a plurality of polishing units.

In this polishing apparatus, different polishing processes are performed on one polishing target in a plurality of polishing units.

In the polishing apparatus according to the present invention, the plurality of polishing sections include at least a first polishing section for roughly polishing the object to be polished, and an object to be polished roughly by the first polishing section. It is preferable to include a second polishing unit that performs finish polishing on the second polishing unit.

In this polishing apparatus, the object to be polished is roughly polished in the first polishing section.
In the second polishing section, finish polishing is performed on the roughly polished workpiece.

The polishing apparatus according to the present invention further comprises:
A third polishing unit is provided between the first polishing unit and the second polishing unit, the third polishing unit including at least one polishing unit for performing medium cutting of an object to be polished that has been roughly cut by the first polishing unit. You may do so.

Furthermore, in the polishing apparatus according to the present invention, each of the plurality of polishing units has a rotatable surface plate, and at least one of the plurality of surface plates has a plurality of surfaces having different hardness characteristics. It is also possible to adopt a configuration in which a polishing pad having a laminated structure composed of the above layers is adhered.

In the polishing apparatus according to the present invention, the polishing pad has a two-layer structure, one layer on the side for polishing the object to be polished is formed of a hard resin, and the other layer is softer than the one layer. The structure may be made of a material, and one of the layers may be made of a polyurethane foam.

Further, in the polishing apparatus according to the present invention, a single-layer polishing pad may be attached to at least one of the plurality of surface plates.

Further, in the polishing apparatus according to the present invention, at least one of the plurality of platens may have a configuration in which at least a part of the polishing surface is a grindstone. A disk shape of 0.0 mm or less, or a ring shape is exemplified. Here, the grindstone may include diamond particles, and the grindstone including diamond may be formed based on a resin. As the base resin, for example, a phenol-based or epoxy-based resin or a glass-based resin is used.

In the polishing apparatus according to the present invention, the grindstone may be formed of a hard resin. As the resin, for example, a polyurethane foam is used.

In the polishing apparatus according to the present invention, the first polishing section may roughly grind the object to be polished by using the above-mentioned grindstone. Further, in the third polishing section,
Medium polishing of the object to be polished is performed using a grindstone having a smaller surface roughness than the first polishing portion, and then, in the second polishing portion, a grindstone having a smaller surface roughness than the third polishing portion is used. Alternatively, the object to be polished may be finished. Alternatively, in the third polishing section, the medium to be polished is medium-cut using a grindstone having a smaller surface roughness than that of the first polishing section, and then, in the second polishing section, Alternatively, the object to be polished may be finished using a polishing pad having a small surface roughness. Alternatively, in the third polishing section, medium polishing is performed using a polishing pad having a smaller surface roughness than that of the first polishing section, and subsequently, in the second polishing section, Alternatively, the object to be polished may be finished using a polishing pad having a small surface roughness.

In the polishing apparatus according to the present invention, the polishing pad of the second polishing section may be a polishing pad having the above-mentioned laminated structure.

Further, in the polishing apparatus according to the present invention, in the first polishing section, the object to be polished is roughly cut using the above-mentioned grindstone, and then, in the second polishing section, the surface is more polished than the first polishing section. The object to be polished may be finished using a polishing pad having a fine roughness.

Further, in the polishing apparatus according to the present invention, in the first polishing section, the object to be polished is roughly cut using the polishing pad, and then, in the second polishing section, the rough polishing is performed more than in the first polishing section. The object to be polished may be finished using a polishing pad having a small surface roughness. Further, the polishing pad of the second polishing section may be a polishing pad having the above-mentioned laminated structure.

In the polishing apparatus according to the present invention, the slurry may be used together with the polishing pad in the second polishing section. Here, the slurry containing, for example, alumina particles is used.

Further, the polishing apparatus according to the present invention may include a cleaning section for cleaning the object to be polished finished in the second polishing section. Further, the cleaning unit may include a cleaning pad formed of a flexible brush.

In the polishing apparatus according to the present invention, for example, a semiconductor integrated circuit or a wafer of a thin-film magnetic head is used as the object to be polished.

In the polishing apparatus according to the present invention, each platen of the plurality of polishing units may be accommodated in one pedestal, and the object to be polished may be sequentially processed in the plurality of polishing units.

The polishing method according to the present invention is a polishing method for polishing and flattening an object to be polished, wherein at least a first polishing step of roughly polishing the object to be polished,
After the first polishing step, a second polishing step of performing a final polishing on the object to be polished which has been roughly cut is included.

The polishing method according to the present invention further comprises:
Before the second polishing step, a third polishing step including at least one polishing step for performing medium-polishing polishing on the object roughly polished by the first polishing step may be included. .

Further, in the polishing method according to the present invention, a plurality of polishing steps may be performed in a plurality of polishing sections included in one pedestal.

A method of manufacturing a semiconductor device according to the present invention includes a flattening step of polishing and flattening a wafer for a semiconductor integrated circuit, wherein the flattening step is performed using the polishing apparatus of the present invention. It is. The polished surface can be, for example, the surface of an interlayer insulating film formed on a metal wiring layer having a dense / dense pattern on a semiconductor wafer.

The method of manufacturing a thin film magnetic head according to the present invention includes a flattening step of polishing and flattening the thin film magnetic head, wherein the flattening step is performed by using the polishing apparatus of the present invention. . The polished surface can be, for example, the surface of an insulating layer formed so as to cover one of the two shield layers of a read head having a magnetoresistive element sandwiched between two shield layers. . Alternatively, the surface of the insulating layer formed so as to cover the magnetic pole tip of the recording head having the magnetic pole tip and the magnetic pole divided into two parts by the magnetic layer may be a polished surface.

[0063]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 shows a first embodiment of the present invention.
1 shows a configuration of a polishing apparatus 1 according to the embodiment. The polishing apparatus 1 is for polishing an object to be polished, for example, a surface of a wafer, and has a pedestal 10. The pedestal 10 has a plurality of, in this embodiment, for example, three polishing units 11A to 11C and one cleaning unit 11D.
Is provided. The polishing units 11A to 11C and the cleaning unit 11D have platens (platens) 12a to 12d, respectively. Each of the surface plates 12a to 12d has a pedestal 1
0 is rotatably arranged on the surface. Surface plate 12
Each of a to 12d is connected to a rotation mechanism (not shown) provided at a lower portion of the pedestal 10 through an opening (not shown) provided in the pedestal 10, and is, for example, counterclockwise viewed from above. It rotates at a predetermined speed in the circumferential direction.

On the pedestal 10, these surface plates 12a-1
Four wafer holders (heads) 14 are arranged to face each 2d. Although not shown in FIG. 1, the wafer holder 14 has a holding portion 14a for holding a wafer.
(See FIG. 2), and the wafer holder 14a is also rotated around a rotating shaft 14b by a spindle motor (not shown).
For example, it rotates at a predetermined speed in a clockwise direction when viewed from above. The surfaces of the surface plates 12a to 12d in the polishing units 11A to 11C and the cleaning unit 11D are:
They have different surface roughness and different hardness. The wafers to be polished are transferred together with the wafer holder 14 to the positions facing the respective platens 12a to 12d in the order of the polishing units 11A to 11C and the cleaning unit 11D so that the polishing and cleaning are performed to different degrees. Has become.

First, the surface plate 12a in the polishing section 11A
The at least a part of the polished surface, for example, the whole surface is made of a grindstone. The grindstone is based on a resin (resin) such as a phenolic resin, and the base resin has diamond particles having a particle diameter of 1,000 to 3,000 or 5,000, and further, about 10,000. Which are dispersed and fixed. The shape of the grindstone is, for example, a circular shape, and its thickness is, for example, 1 mm or less. The grindstone may be a diamond grindstone (vitrified) using a glass-based resin as a base. Further, without using diamond particles, for example, a porous polyurethane foam or a phenol-based resin or an epoxy-based resin may be used. You may make it comprise only such a hard resin.

FIG. 2 shows II-II in the polishing section 11A of FIG.
1 shows an example of a cross-sectional configuration along a line. In the figure, the holding portion 14a of the wafer holder 14 is constituted by a porous chuck. The wafer W is held in the holding portion 14a by evacuating the hollow portion 14c provided in the wafer holder 14 as shown by an arrow a in the drawing.
And is held by the In the polishing section 11A, a lubricant 16 is supplied from a nozzle 15. Lubricants include pure water,
Examples thereof include oil, isopropyl alcohol, alumina-based slurry and silica-based slurry.

In the present embodiment, first, the polishing section 1
In 1A, while supplying the lubricant 16 from the nozzle 15, the polishing of the wafer W is performed by the surface plate 12a (rough cutting).
Is what you do. As a result, the projections of the insulating film covering the many different patterns existing in the wafer W, for example, the aggregate portion of the fine wiring patterns, the large pattern or the isolated pattern, are uniformly polished and removed. I have. In the polishing section 11A, the surface plate 12
Since a is composed of a grindstone, the polished surface is hard and scratches occur slightly, but the polished surface does not show any dependence on the wafer pattern. Note that the polishing section 11A corresponds to the "first polishing section" of the present invention.

Next, the surface plate 12b in the polishing section 11B
Has a single-layer polishing pad 13b made of, for example, a hard polyurethane foam adhered to the surface thereof. Here, polishing is performed using the polishing pad 13b and a polishing liquid supplied from a nozzle (not shown). Examples of the slurry contained in the polishing liquid include an alumina-based or silica-based slurry, or a mixture of both. The polishing section 11B removes scratches and polishing distortions that have been generated slightly in the polishing section 11A by using the polishing pad 13b, and performs medium polishing (that is, between the first rough polishing and the final polishing). (Medium polishing).
The polishing section 11B corresponds to the "third polishing section" of the present invention. For example, in a thin-film magnetic head, the polishing section 1
In 1B, an insulating layer made of alumina is polished until a magnetic layer (a shield magnetic film or a recording magnetic pole) formed of permalloy or the like is exposed to the surface. The third polishing unit may be a polishing unit that performs two or more different types of polishing depending on the application.

The surface plate 12c of the polishing section 11C has a plurality of layers, for example, a two-layer polishing pad 13c adhered to the surface thereof. FIG. 3 shows a polishing pad 1 including a surface plate 12c.
3C illustrates an example of a cross-sectional configuration of 3c.

[0071] Polishing pad 13c has a two-layer structure of the surface layer 13c ₁ and a lower layer 13c _2. Surface layer 13c
_1, for example, hard and formed by a polyurethane foam porous lower layer 13c _2, for example a polyurethane, a material which is resilient like rubber Rubber, or anything softer than the surface layer 13c ₁ material, ceramics, plastic Is formed of a hard material such as Polishing unit 1
1C uses the polishing pad 13c to lightly polish and finish the surface of the wafer. The polishing section 11C corresponds to the "second polishing section" of the present invention. Here, also in this case, a polishing liquid containing the same slurry as in the polishing section 11B is supplied from the nozzle 15 onto the polishing pad 13c.

The surface plate 12d of the cleaning section 11D has a single-layer cleaning pad 13d having a long bristle brush attached to the surface thereof. The cleaning unit 11D uses the cleaning pad 13d to completely remove (clean) contaminants due to micro-scratch or slurry generated in the previous process using pure water or alcohol as a lubricant. This cleaning unit 11D corresponds to the “cleaning unit” of the present invention. In addition, this cleaning unit may be configured by two or more cleaning units having different cleaning degrees depending on the application.

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

In this polishing apparatus 1, each of the polishing units 11A to 11A
In 1C and the cleaning section 11D, the surface plates 12a to 12d
Each of them and the wafer holder 14 holding the wafer W rotate in directions opposite to each other. Wafer W as object to be polished
Are polishing units 11A to 11C together with the wafer holder 14.
And the surface plates 12a to 12 in the order of the cleaning unit 11D.
d and is polished and cleaned to different degrees.

That is, first, in the polishing section 11A,
With the surface plate 12a made of a hard grindstone, the protrusions of the insulating film covering over a number of different patterns (for example, a collection of fine patterns, a large pattern or an isolated pattern) existing in the wafer W are uniformly formed. Polished and removed (rough cut). In this case, since the polished surface of the surface plate 12a is hard, the pattern dependence of the wafer W is not seen on the polished surface.

The wafer W roughly cut in the polishing section 11A is transferred to the polishing section 11B. In the polishing section 11B, a hard polishing pad 13 having a single-layer structure is used.
As a result of b, scratches and polishing distortions that have been generated slightly on the wafer on the surface plate 12a are removed (medium cutting). In addition,
For example, in the thin-film magnetic head, in the polishing section 11B, the insulating layer made of alumina is polished until just before the magnetic layer (shield magnetic film or recording magnetic pole) formed of permalloy or the like is exposed on the surface.

The wafer W subjected to the middle cutting in the polishing section 11B is then transferred to the polishing section 11C. In the polishing section 11C, polishing is finished by a polishing pad 13c having a two-layer structure. Here, polishing pad 1
In 3c, the surface layer 13c ₁ that is constituted by a polyurethane foam or the like rigid, by configuring to support the lower layer 13c ₂ formed by softer than the surface layer 13c ₁ material, between the surface and the polishing surface of the wafer W Can be exposed horizontally. In this step, for example, in the manufacturing process of the thin-film magnetic head, scratches and the like are hardly formed on the surface layer of a metal layer such as a coil formed of permalloy or copper. Note that even if scratches or the like occur, they do not cause damage that cannot be repaired in a later step.

The wafer W, which has been polished and finished in the polishing section 11C, is finally sent to the cleaning section 11D, where the cleaning pad 13d, together with a lubricant such as pure water, generates micro scratches generated in the previous step. And contaminants from the slurry are completely washed away. This completes the finish and ends the series of planarization processes.

As described above, the polishing apparatus 1 of the present embodiment has the three polishing sections 11A to 11C, and the rough processing, the medium cutting and the finishing of the wafer W are performed in these polishing sections 11A to 11C. Then, the wafer W is flattened. That is, the wafer W is roughly polished by the surface plate 12a made of a coarse and hard grindstone in the polishing section 11A, and thereafter, is subjected to medium polishing by the relatively hard polishing pad 13b in the polishing section 11B.
As a result, the convex portions of the wafer W are removed without pattern dependency and without generating large scratches and cracks. After that, in the polishing section 11C, fine polishing is performed by the fine and soft polishing pad 13c. Finally, in the cleaning section 11D, micro cracks and scratches are completely removed by the long and soft cleaning pad 13d.

As a result, in this embodiment, the flattening process can be performed with high accuracy, so that the performance of the semiconductor integrated circuit and the composite thin film magnetic head and the like can be improved, and the manufacturing yield can be improved.

Further, in this embodiment, since the four wafer holders 14 are sequentially moved to the polishing units 11A to 11C and the cleaning unit 11D, the processing of the wafer W can be performed continuously, and the efficiency can be improved. A planarization process can be performed. At this time, if an independent processing time is set for each of the polishing units 11A to 11C and the cleaning unit 11D, different polishing processes can be performed for each wafer according to the processing target. If the processing times of the wafers do not match in each part, the polishing parts 11A to 11A
What is necessary is just to make a wafer wait in 1C and the washing | cleaning part 11D.

[Second Embodiment] FIG. 4 shows a second embodiment of the present invention.
1 shows a configuration of a polishing apparatus 2 according to the embodiment. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

This polishing apparatus 2 comprises two polishing units 21A,
21B and a washing unit 21C. Polishing unit 21
A, 21B and the cleaning unit 21C are respectively
a to 22c, and a wafer holder (head) 24 is arranged to face each of the surface plates 22a to 22c. The surfaces of the surface plates 22a to 22c have different surface roughnesses and different hardnesses, and the wafer W is transferred together with the wafer holder 24 in the order of the polishing units 21A and 21B and the cleaning unit 21C. Is polished and cleaned.

The surface plate 22a of the polishing section 21A has a single-layer hard polishing pad 23a made of a hard resin, for example, a polyurethane foam adhered to the surface thereof. Here, a polishing liquid containing slurry is supplied onto the polishing pad 23a from a nozzle (not shown). As the slurry, an alumina-based or silica-based slurry or a mixture of both is used. In the polishing section 21A, similarly to the first embodiment, the surface plate 22a may be formed of a grindstone, and polishing using a lubricant may be performed. The polishing unit 21A firstly uses the surface plate 22a to
A large number of different patterns existing in a wafer (for example, an aggregate portion of fine patterns, a large pattern or an isolated pattern, etc.) are uniformly polished and removed (rough-cut) on a convex portion of an insulating layer which covers the pattern. In the present embodiment, the polishing section 21A is the “first polishing section” of the present invention.
It corresponds to. In the surface plate 22a, since the polishing surface is the hard polishing pad 23a, the pattern dependence of the wafer W is not seen. In the case of a thin-film magnetic head, for example,
In the polishing section 21A, similarly to the polishing section 11B of the first embodiment, the insulating layer made of alumina or the like is polished until just before the shield magnetic pole or the recording magnetic pole of permalloy or the like is exposed on the surface. I have.

The surface plate 22b of the polishing section 21B has a two-layer polishing pad 23b adhered to the surface thereof. The polishing pad 23b has the same configuration as the polishing pad 13c of the first embodiment, for example. Polishing unit 2
1B uses the polishing pad 23b to lightly polish the surface of the wafer, remove scratches and polishing distortions that have been generated slightly in the polishing section 21A, and perform finishing. This polishing section 21B is the “second polishing section” of the present invention.
It corresponds to. Here also, the polishing liquid containing the slurry is supplied from the nozzle onto the polishing pad 23b. When the object to be polished is a thin-film magnetic head, the thickness of the shield magnetic pole, the recording magnetic pole and the like after being polished by the polishing unit 21A is accurately controlled in the polishing unit 21B, and the recess is set to 0.05 μm. In the following, scratches on the surface of the magnetic layer made of permalloy are removed.

On the surface of the surface plate 22c in the cleaning section 21C, for example, the cleaning pad 11 of the first embodiment is placed.
A cleaning pad 23c having the same configuration as that of d is stuck. The cleaning unit 21C uses the cleaning pad 23c to
Pure water or alcohol is used as a lubricant to completely remove (clean) contaminants due to micro-scratch and slurry generated in the previous process. This cleaning unit 21C
This corresponds to the “cleaning section” of the present invention.

In the polishing apparatus 2 of the present embodiment, first, in the polishing section 21A, rough polishing is performed by a polishing pad 23a formed of, for example, a hard polyurethane foam, so that a large number of different patterns existing in the wafer W are formed. Are uniformly polished and removed. The wafer W that has been roughly cut in the polishing section 21A is transferred to the polishing section 21B.

In the polishing section 21B, the scratches and polishing distortions which have been generated slightly on the wafer W in the polishing section 21A are removed by the polishing pad 23b having the two-layer structure.
Finishing is done. In the thin-film magnetic head, for example, in the polishing portion 21A, the insulating layer made of alumina is polished until the shield magnetic pole and the recording magnetic pole formed of permalloy or the like are exposed on the surface.

Finally, the contaminants generated in the previous step by the micro scratches and the slurry are completely removed by the cleaning pad 23c in the cleaning section 21C of the wafer finished in the polishing section 21B.

As described above, in the polishing apparatus 2 of the present embodiment, the polishing pads 23a and 23 having different surface roughnesses and different hardnesses in the two polishing portions 21A and 21B.
By b, each of the steps of rough cutting and finishing is performed, and thereafter, the cleaning is performed in the cleaning unit 21C. As a result, also in this embodiment, the flattening of the wafer is performed with high accuracy, the performance of devices such as a semiconductor integrated circuit and a composite thin-film magnetic head is improved, and the yield is improved.

Next, as a specific application example of the polishing apparatuses 1 and 2, a flattening process of a multilayer wiring structure in a semiconductor integrated circuit, a shield layer of a thin-film magnetic head and a pole tip of a top pole (a pole tip) ) Will be described.

First, FIGS. 5A and 5B show an example in which the present invention is applied to a flattening process of a multilayer wiring of a semiconductor integrated circuit. FIG. 4A shows a silicon oxide film (SiO 2 film) formed on a plurality of metal wiring patterns 31 having a thickness of, for example, 0.7 μm on a field oxide film 30 formed on a silicon substrate.
_This shows a state in which the interlayer insulating film 32 of ₂ ) is formed with a thickness of about 2 μm. Fine metal wiring pattern 31
Are formed in the interlayer insulating film 32 in the region where
Are formed. From this state, the polishing apparatuses 1 and 2
FIG. 5B shows a state in which the surface is flattened by the method shown in FIG.
It is.

As is apparent from this figure, in the present embodiment, not only the convex portion 32a of the portion where the metal wiring patterns 31 are gathered but also the portion between the gathered portions of the metal wiring patterns 31. Are also accurately flattened. Therefore, it is possible to prevent a wiring layer (not shown) thereabove from being disconnected or causing a defect due to electromigration. As a result, in the multilayer wiring structure of the semiconductor integrated circuit, it is possible to perform a flattening process without pattern dependency, thereby improving the reliability of the device and significantly improving the manufacturing yield.

FIGS. 6A to 6C show an example in which the present invention is applied to a flattening process of a shield layer of a thin-film magnetic head and a pole tip (pole tip) of an upper magnetic pole. FIG. 2A shows a substrate 40 made of Altic.
For example, an insulating layer 41 made of alumina by a sputtering method.
Is deposited with a thickness of about 3 to 5 μm,
On top, for example, by plating, for example, permalloy (Ni
A lower shield layer 42 for a reproducing head made of a magnetic material such as Fe) is formed to a thickness of 2 to 3 μm, and an insulating layer 43 made of alumina of 3 to 4 μm is formed on the lower shield layer 42. Is represented. On the lower shield layer 42, a protrusion 43a is formed in the insulating layer 43.

FIG. 6B shows a state in which the surface of the insulating layer 43 has been flattened by the polishing apparatuses 1 and 2 from this state. In such a thin film head, the surface is polished up to the lower shield layer 42 so that the lower shield layer 42 is exposed on the surface of the insulating layer 43. Therefore, conventionally,
As described above, it is inevitable that a step is generated between the insulating layer 43 and the lower shield layer 42 and the insulating layer 43 or the lower shield layer 42 has a recess structure. On the other hand, in the present embodiment, since the polishing processes having different polishing hardnesses are performed in a plurality of stages, the flattening process can be performed without pattern dependency, and the insulating layer 43 and the lower shield layer can be formed. Recesses are less likely to occur between the two and the polishing speed and the controllability of the remaining film thickness are improved.

In this embodiment, thereafter, as shown in FIG. 6C, the lower shield gap film 44, the magnetoresistive film 45, and the extraction electrode layer (lead wire) connected to the magnetoresistive film 45. After forming the upper shield gap film 47, the upper shield layer and the lower magnetic pole 48 to a thickness of about 2 to 4 μm, an insulating layer 49 made of alumina is formed again to a thickness of 3 to 5 μm. 49
Is polished by the polishing apparatuses 1 and 2. Also in this embodiment, the occurrence of the recess is small. Then, after forming the recording gap film 50 to a thickness of 0.2 to 0.3 μm, the magnetic pole tip (pole tip) 51 a is
An insulating layer 5 of 3 μm thickness and made of alumina again
After forming 2 with a thickness of 3 to 4 μm, it is polished. Also in this embodiment, the occurrence of the recess is small. Finally, a thin film coil (not shown), an upper magnetic layer (top pole) 51b, an overcoat layer (not shown) and the like are formed, and the manufacturing process of the thin film magnetic head is completed.

As described above, in order to improve the performance of the thin-film magnetic head, the polishing amount is controlled by a polishing apparatus, the thickness of the lower shield after polishing, the thickness of the upper shield layer, and finally, the pole tip portion. (Pole tip)
Had to be excellent in uniformity within the wafer. However, in the conventional polishing apparatus, a recess is generated between the lower shield layer and the upper shield layer and the insulating layer when polishing the tip of the magnetic pole, which hinders the performance of the thin-film magnetic head. On the other hand, in the present embodiment, a plurality of polishing processes having different degrees of polishing are performed.
The controllability of the polishing rate between the insulating layer and the magnetic layer exposed from the insulating layer is improved. Further, the uniformity of the thickness in the wafer is good, and the surface of the magnetic layer is free from scratches and the like, the recess is small, and the reproducibility is improved.
Therefore, it is easy to form a narrow track, which is an important process for a thin film magnetic head, and in particular, the performance of a recording head is significantly improved.

[Embodiment] FIG. 7 shows a thin-film magnetic head in which an alumina insulating film of about 6 μm is formed on a permalloy pattern of about 3.0 μm of a shield layer by a conventional method, and then a No. 3000 biton grindstone. The data (a) polished by about 2 μm and the conventional IC1000 and Suba40
FIG. 3 shows data (b) obtained by measuring a step after polishing by 3 μm using a polishing pad having a two-layer structure consisting of zero. In FIG. 7, the horizontal axis represents the measurement position (mm) in the wafer, and the vertical axis represents the remaining film thickness (nm). In the result of (a), the permalloy shield layer was not exposed, and it was unknown whether scratches occurred on the surface state. However, in other examples in which the permalloy shield layer was exposed, many scratches were formed on the surface of the shield layer. The result of (b) is a result of measuring a step on the surface of the wafer in a state where the permalloy shield layer is exposed. Although the surface of the shield layer depends on the selection of the slurry, micro scratches were formed in some places. However, these were not fatal. The recess was relatively large at 150 to 300 nm, depending on the selection of the slurry.

On the other hand, FIGS. 8A and 8B show the results of flattening by the polishing apparatus 1 according to the present embodiment, respectively. In FIGS. 7A and 7B, the numbers 1 to 6 on the horizontal axis indicate horizontal positions.
This corresponds to the measurement position in the wafer W as shown in FIG. Resin series No. 3000 was used for the whetstone. As a sample, a magnetic layer made of permalloy with a thickness of 3 μm
An insulating film made of alumina having a thickness of 4.5 μm was formed, and flattened by the polishing apparatus 1. FIG.
3 shows data of the remaining film thickness of an insulating layer made of alumina after polishing by μm. Here, in FIG.
(A) shows the initial thickness of the insulating layer, (b) shows the thickness of the insulating layer after polishing, and (c) shows the polishing amount of the insulating layer.

On the other hand, FIG. 8B shows data obtained by measuring the remaining film thickness of the magnetic layer made of permalloy after polishing similarly at 1.5 μm. Here, in FIG.
(A) shows the initial film thickness of the magnetic layer, (b) shows the film thickness of the magnetic layer after polishing, and (c) shows the recess amount. Thereby, when the polishing apparatus 1 according to the present embodiment is used,
It can be seen that the film thickness is uniform over the entire wafer, and the wafer is flattened accurately. Also, the recesses between the insulating film made of alumina and the shield layer made of permalloy are all suppressed to 50 nm or less.

Although the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the above-described embodiments and examples, and can be variously modified. For example, the number of polishing units excluding the cleaning unit is three in the first embodiment and two in the second embodiment, but the number is arbitrary as long as there are at least two polishing units. . Specifically, the third polishing unit for performing the medium cutting may be configured to include a plurality of polishing units for performing polishing of different degrees. Further, the combination of the grindstone and the polishing pad is not limited to the above embodiment, and various combinations are possible. In short, it is only necessary that a plurality of polishing units can sequentially and continuously perform from coarse-grain polishing to fine-grain polishing in one apparatus.

In the above-described embodiment, the transfer of the wafer W between each polishing section and the cleaning section is performed by the wafer holder 1.
By rotating the four sides, the pedestal 1
The side may be rotated.

Further, in the above embodiment, a disc-shaped grindstone is used as a grindstone for performing rough cutting. However, as shown in FIG. 10, a ring-shaped (or cup-shaped) grindstone 60 is used. May be used to polish the surface of the wafer W. At this time, the whetstone 60
As shown by the arrow in the figure, the surface of the wafer W is rotated by a rotating means (not shown) and relatively moved by a moving means (not shown) to polish the entire surface of the wafer W.

In the above embodiment, each of the first to third polishing units sequentially polishes one workpiece, but in order to improve the productivity, the first to third polishing units are polished. In each polishing section of the polishing section, it is also possible to simultaneously perform two or more polishing operations of the same content so that a plurality of objects to be polished can be simultaneously processed.

Further, in the above embodiment, the polishing section and the cleaning section are integrated, but the polishing section and the cleaning section may be provided as separate devices. FIG. 11 shows an example of such a case, and a polishing apparatus 70 having three polishing units 71A to 71C.
And a cleaning device 80 having two cleaning units 81A and 81B and a drying unit 81C having different cleaning degrees are connected by an underwater elevator 90. The polishing units 71A to 71C in the polishing apparatus 70 are each constituted by a surface plate 72 and a wafer holder 73, and correspond to the polishing units 11A to 11C in the first embodiment. In the polishing apparatus 70, the wafer W sent through the loader 74 is transferred between the polishing units 71A to 71C by the arm robot 75, and roughing, medium cutting, and finishing polishing are performed. Then, the finished wafer W is sent to the cleaning device 80 in a wet state by the underwater elevator 90. In the cleaning device 80, coarse cleaning is performed in the cleaning unit 81A, precision cleaning is performed in the cleaning unit 81B, and spin drying is performed in the drying unit 81C in this order. Finally, the cleaning device 80 is taken out of the cleaning device 80 via the unloader 82.

In the present invention, the object to be polished is not limited to the one described in the above embodiment, but may be another portion or another device on a wafer for a semiconductor integrated circuit or a thin film magnetic head. For example, in the case of a thin film magnetic head, as described above, the ABS is polished in the final process and the throat height is adjusted, and the polishing apparatus and the polishing method of the present invention are also applied to the polishing of the ABS. Is possible.

[0107]

As described above, claims 1 to 32 are provided.
According to the polishing apparatus of any one of the above, or the polishing method of any one of the claims 33 to 35,
Since the polishing objects of different degrees are performed on the object to be polished, it is possible to sequentially perform a plurality of stages of polishing processes from rough polishing to fine finishing. Therefore, the flattening process can be performed with high accuracy, and the precision of fine processing of a semiconductor integrated circuit, a thin film magnetic head, and the like can be improved, and the production yield can be improved.

According to the method of manufacturing a semiconductor device of the present invention, the flattening step is performed by using the polishing apparatus of the present invention. This has the effect of improving the precision of microfabrication and improving the production yield.

Further, any one of claims 38 to 40
In the method for manufacturing a thin film magnetic head according to the above item, the flattening step is performed using the polishing apparatus according to any one of the above items 1 to 32, so that the precision of fine processing is improved. This has the effect of improving the manufacturing yield.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of a polishing apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a cross-sectional configuration of a polishing unit along a line II-II in FIG.

FIG. 3 is a cross-sectional view illustrating a configuration of a polishing pad in the polishing apparatus illustrated in FIG.

FIG. 4 is a perspective view illustrating a configuration of a polishing apparatus according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a step of planarizing a semiconductor integrated circuit by the polishing apparatus of the present invention.

FIG. 6 is a cross-sectional view for explaining a flattening step of the thin-film magnetic head by the polishing apparatus of the present invention.

FIG. 7 is a characteristic diagram for explaining a polishing result when a conventional polishing apparatus is used.

FIG. 8 is a characteristic diagram for explaining a polishing result when the polishing apparatus of the present invention is used, wherein FIG. 8A shows the polishing result of alumina, and FIG. 8B shows the polishing result of Permalloy.

FIG. 9 is a plan view for explaining measurement points of a wafer in the characteristic diagram of FIG. 8;

FIG. 10 is a perspective view illustrating an example of a grindstone used in the polishing apparatus of the present invention.

FIG. 11 is a plan view for explaining a schematic configuration of still another embodiment of the present invention.

FIG. 12 is a cross-sectional view of a CMOS circuit as an example to which a planarization process by a polishing apparatus is applied.

FIG. 13 is a cross-sectional view of a thin-film magnetic head as another example to which a flattening process by a polishing apparatus is applied.

FIG. 14 is a perspective view illustrating a configuration of a conventional polishing apparatus.

FIG. 15 is a cross-sectional view for describing a problem when a conventional polishing apparatus is used for a planarization process of a semiconductor integrated circuit.

FIG. 16 is a cross-sectional view for explaining a problem when a conventional polishing apparatus is used for a flattening process of a thin-film magnetic head.

[Explanation of symbols]

1, 2, polishing machine, 10 pedestal, 11A to 11C, 21
A, 21B: polishing section, 11D, 21C: cleaning section, 12a
~ 12d ... surface plate, 13b, 13c, 23a, 23b ... polishing pad, 14 ... wafer holder (head), 15 ... nozzle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yudai Horinaka 1-1-13 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Toshio Kubota 1-13-1 Nihonbashi, Chuo-ku, Tokyo F-term in DC Corporation (reference) 3C043 BA04 BA09 BA16 CC02 CC06 CC07 CC11 CC13 DD05 3C058 AA02 AA06 AA07 AA09 AA18 AC04 CB01 CB05 DA02 DA17

Claims (40)

[Claims] 1. A polishing apparatus for polishing and flattening an object to be polished, comprising a plurality of polishing units for performing polishing processes of different degrees on one object to be polished. Polishing equipment. 2. The polishing apparatus according to claim 1, wherein the plurality of polishing units include at least a first polishing unit configured to roughly polish the object to be polished, and a first polishing unit configured to roughly polish the object to be polished by the first polishing unit. The polishing apparatus according to claim 1, further comprising a second polishing unit that performs finish polishing. 3. The method according to claim 1, further comprising, between the first polishing section and the second polishing section, at least one step of performing medium-polishing on the workpiece that has been roughly cut by the first polishing section.
The polishing apparatus according to claim 2, further comprising a third polishing unit including two polishing units. 4. The plurality of polishing units each have a rotatable surface plate, and at least one of the plurality of surface plates has a laminated structure including a plurality of layers having different hardness properties from each other. The polishing apparatus according to any one of claims 1 to 3, wherein the polishing pad is attached. 5. The polishing pad has a two-layer structure, one layer on the side for polishing an object to be polished is formed of a hard resin, and the other layer is formed of a material softer than the one layer. The polishing apparatus according to claim 4, wherein the polishing is performed. 6. The polishing apparatus according to claim 5, wherein said one layer is formed of a polyurethane foam. 7. The polishing pad according to claim 4, wherein a polishing pad having a single-layer structure is attached to at least one of the plurality of surface plates. Polishing equipment. 8. The polishing apparatus according to claim 1, wherein at least one of the plurality of surface plates has at least a part of a polishing surface formed of a grindstone. 9. The polishing apparatus according to claim 8, wherein the whetstone has a disk shape, and has a thickness of 1.0 mm or less. 10. The polishing apparatus according to claim 8, wherein the whetstone has a ring shape. 11. The polishing apparatus according to claim 8, wherein the grindstone includes diamond particles. 12. The grinding wheel containing diamond is formed based on a resin.
A polishing apparatus according to claim 1. 13. The polishing apparatus according to claim 12, wherein the base resin is a phenol-based or epoxy-based resin. 14. The polishing apparatus according to claim 12, wherein said base resin is a glass-based resin. 15. The polishing apparatus according to claim 8, wherein the grindstone is formed of a hard resin. 16. The polishing apparatus according to claim 15, wherein the resin is a polyurethane foam. 17. The polishing apparatus according to claim 8, wherein an intermediate layer made of a resilient material is interposed between the grinding wheel and the surface plate. . 18. The method according to claim 8, wherein the first polishing section is used.
The polishing apparatus according to claim 2, wherein the object to be polished is roughly cut using the grindstone according to any one of claims 17 to 17. 19. The method according to claim 19, wherein the third polishing unit includes the first polishing unit.
The medium to be polished is subjected to medium grinding using a grindstone having a smaller surface roughness than that of the polishing portion, and then, in the second polishing portion, a grindstone having a smaller surface roughness than the third polishing portion is used. 19. The polishing apparatus according to claim 18, wherein the polishing target is finished by polishing. 20. The method according to claim 19, wherein the third polishing section includes the first polishing section.
The medium to be polished is medium-ground using a grindstone having a smaller surface roughness than that of the polishing portion, and then, in the second polishing portion, a polishing pad having a smaller surface roughness than the third polishing portion is formed. 19. A polishing method for finishing an object to be polished.
A polishing apparatus according to claim 1. 21. The method according to claim 21, wherein:
Polishing the object to be polished using a polishing pad having a smaller surface roughness than the polishing portion, and then, in the second polishing portion, a polishing pad having a smaller surface roughness than the third polishing portion. 19. The polishing apparatus according to claim 18, wherein the object to be polished is finished by using a polishing machine. 22. The polishing pad according to claim 20, wherein the polishing pad of the second polishing section is a polishing pad having a laminated structure according to any one of claims 4 to 6. Polishing equipment. 23. The first polishing section according to claim 8, wherein
A rough polishing of an object to be polished using the grindstone according to any one of claims 14 to 14, and subsequently, a polishing pad having a smaller surface roughness in the second polishing section than in the first polishing section. 3. The polishing apparatus according to claim 2, wherein the object to be polished is finished by using the polishing. 24. The first polishing section according to claim 7, wherein
The rough polishing of the object to be polished is performed using the polishing pad according to the above item, and the finishing of the object to be polished is performed using a polishing pad having a smaller surface roughness than the first polishing unit in the second polishing unit. The polishing apparatus according to claim 2, wherein polishing is performed. 25. The polishing pad according to claim 23, wherein the polishing pad of the second polishing section is a polishing pad having a laminated structure according to any one of claims 4 to 6. Polishing equipment. 26. The polishing apparatus according to claim 2, wherein a slurry is used together with the polishing pad in the second polishing section. 27. The polishing apparatus according to claim 26, wherein the slurry contains alumina particles. 28. The polishing apparatus according to claim 2, further comprising a cleaning section for cleaning an object to be polished finished in the second polishing section. 29. The polishing apparatus according to claim 28, wherein the cleaning section has a cleaning pad made of a flexible brush. 30. The polishing apparatus according to claim 1, wherein the object to be polished is a wafer for a semiconductor integrated circuit. 31. The polishing apparatus according to claim 1, wherein the object to be polished is a wafer for a thin film magnetic head. 32. The polishing machine according to claim 1, wherein each surface plate of the plurality of polishing units is accommodated in one pedestal, and the object to be polished is sequentially processed in the plurality of polishing units. Item 2. The polishing apparatus according to Item 1. 33. A polishing method for polishing and flattening an object to be polished, wherein at least a first polishing step of roughly polishing the object to be polished; And a second polishing step of performing final polishing on the polished workpiece after the rough cutting. 34. A third polishing step further comprising, before the second polishing step, at least one polishing step of performing medium polishing on the object roughly polished in the first polishing step. The polishing method according to claim 33, further comprising a polishing step. 35. The polishing method according to claim 33, wherein the plurality of polishing steps are performed in a plurality of polishing units included in one pedestal. 36. A method for manufacturing a semiconductor device, comprising: a flattening step of polishing and flattening a wafer for a semiconductor integrated circuit, wherein the flattening step is performed according to any one of claims 1 to 32. A method for manufacturing a semiconductor device, wherein the method is performed using a polishing apparatus. 37. The method of manufacturing a semiconductor device according to claim 36, wherein the polished surface is a surface of an interlayer insulating film formed on a metal wiring layer having a dense / dense pattern on a semiconductor wafer. 38. A method for manufacturing a thin-film magnetic head, comprising a flattening step of polishing and flattening a thin-film magnetic head, wherein the flattening step is performed by the polishing apparatus according to claim 1. A method for manufacturing a thin-film magnetic head, comprising: 39. The polished surface is a surface of an insulating layer formed so as to cover one of the two shield layers of a read head having a magnetoresistive element sandwiched between two shield layers. The method for manufacturing a thin-film magnetic head according to claim 38, wherein: 40. The polished surface is the surface of an insulating layer formed to cover the magnetic pole tip of a recording head having a magnetic pole tip and a magnetic layer divided into two parts by a magnetic layer. Item 39. The method for manufacturing a thin film magnetic head according to Item 38.