JP2003103455A - Work holding board and polishing device and polishing method for work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing device and a polishing method, particularly a work holding board for polishing a wafer so that there are no irregular parts of a nanotopography level. SOLUTION: Microscopic pores are formed in a work holding face of the work holding board having a work holding board body for holding one principal plane of a work and polishing another principal plane into a mirror finish.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer holding plate which can effectively prevent the generation of irregularities at the nanotopography level, a wafer polishing apparatus and a polishing method using the wafer holding plate.

[0002]

Related Art Conventionally, a method of manufacturing a work such as a silicon wafer used as a semiconductor substrate material is generally a single crystal using a Czochralski (CZ) method or a floating zone (FZ) method. A crystal growth step of manufacturing an ingot and a wafer processing step of slicing the single crystal ingot and processing at least one main surface into a mirror surface are performed. In more detail, the wafer processing step is a slicing step for slicing a single crystal ingot to obtain a thin disk-shaped wafer, and the wafer obtained by the slicing step is cracked to prevent cracking. A chamfering step for chamfering the outer peripheral portion, a lapping step for flattening this wafer, an etching step for removing the processing strain remaining on the chamfered and lapped wafer, and a polishing (polishing) step for mirrorizing the wafer surface. The method has a cleaning step of cleaning the polished wafer to remove the polishing agent and foreign matter attached to it. The above-mentioned wafer processing step shows the main steps, and other steps such as a heat treatment step may be added, the same step may be performed in multiple stages, or the order of steps may be changed.

Among these processes, in the polishing (polishing) process, a wax mount batch type single-side polishing apparatus for sticking a plurality of wafers to a work holding plate made of glass or ceramic with wax and polishing one side is the mainstream at present. Is. A work holding plate holding wafers is placed on a surface plate having a polishing cloth attached thereto, a load is applied to the top ring, and polishing is performed while rotating the surface plate and the top ring. In addition to this, there are various types of polishing devices. For example, a double-sided polishing method in which both sides are mirror-finished at the same time like lapping, a single-wafer method in which wafers are vacuum-sucked and held on a work holding plate one by one, wafers are backed without using an adhesive such as wax. There are various methods such as a wax-free polishing method in which polishing is performed while holding the pad and template.

[0004]

When polishing is carried out by the above various polishing apparatuses, slight irregularities may be observed on the wafer surface. This is the level of unevenness that is observed when observing with a magic mirror image or when evaluating unevenness in a minute area called nanotopography.

Particularly, it is often observed when the holding surface of the work holding board is polished by a holding board coated with an epoxy resin or the like, or when a wax or the like is adhered and held on a plate. Further, even when held by the backing pad and the template, it may be transferred to the wafer surface after polishing due to the thickness unevenness of the backing pad or the adhesive unevenness when the backing pad itself is bonded to the holding plate.

Nanotopography (also called nanotopology) is unevenness having a wavelength of about 0.1 mm to 20 mm and an amplitude of about several nm to 100 nm.
As an evaluation method, a square block area having a side of about 0.1 mm to 10 mm or a circular block area having a diameter of about 0.1 mm to 10 mm (this range is WINDOW SIZ
In a region such as E, the height difference (P-V value; peak to valley) of the unevenness on the wafer surface is evaluated. This P-V value is also called Nanotopography Height or the like. For nanotopography, it is particularly desired that the maximum value of the unevenness present in the evaluated wafer surface is small.

When metal wiring is formed on a wafer in the device manufacturing process, an insulating film is formed on the metal wiring, and the insulating film is polished, the presence of the unevenness at the above level becomes a problem. It's starting.

The present invention has been made in view of the above circumstances, and a polishing apparatus and a polishing method for polishing a wafer so as to prevent nanotopography-level irregularities from occurring.
In particular, the object is to provide a work holding board.

[0009]

It has been clarified that when a wafer is held on the work holding surface of a work holding plate, foreign matter, water, or air pools are generated, which deteriorates nanotopography. This was particularly noticeable when the holding surface of the work holding plate was coated with a resin such as epoxy resin.

Conventionally, there is a problem that irregularities on the back surface of the wafer and the work holding surface of the work holding plate are transferred to the polishing surface of the wafer. Therefore, the back surface of the wafer and the work holding surface of the work holding plate are flattened or the shape of the polishing cloth is changed. It has been carried out by polishing or the like so as to conform to the surface. As a result, foreign matter, water, or air pools are likely to be generated, and nanotopography is deteriorated at that portion.

The work holding plate of the present invention is a work holding plate having a work holding plate body for holding one main surface of a work and mirror-polishing the other main surface. The feature is that micropores are formed.

By doing so, it becomes difficult for foreign matter, water, or air pools between the back surface of the wafer and the holding surface of the work holding plate to occur, and nanotopography is not deteriorated.

Specifically, the work holding plate having micropores formed on the work holding surface is an inorganic or organic system in which particles which can dissolve the surface of the work holding plate body with a dissolving agent such as water or a solvent are added. It is obtained by coating with a coating agent and subjecting the surface of the coating agent layer to dissolution treatment with a dissolving agent such as water or a solvent. In this way, it is preferable to form pores on the surface of the coating agent layer of the work holding plate body. The surface of the coating agent layer in which the pores are formed may be the work holding surface.

It is preferable to use EDTA (ethylenediaminetetraacetic acid), water-soluble cellulose particles or the like as the particles which can be dissolved with a dissolving agent such as water or a solvent.

By using particles that can be dissolved with a solubilizer such as water or a solvent in this way, it is possible to easily form pores of any size by controlling the diameter of particles to be added. Since the shape of the pore is transferred to the surface of the wafer when the pore diameter becomes large, the pore diameter is preferably 0.5 mm or less. The lower limit is preferably 0.02 mm or more. Particularly preferably, the pore diameter is several tens of μm or more.

As another example of the method for forming pores on the work holding surface of the work holding plate, hollow particles made of a material which can be removed by polishing are added to the coating agent, and the work holding plate main body is added. It is also possible to form a pore on the surface of the coating agent layer by coating the surface of the coating agent layer and polishing the surface of the coating agent layer to remove the shell portion of the hollow particles by polishing. Also in this case, the surface of the coating agent layer in which the pores are formed is preferably used as the work holding surface. Further, if the particles are soluble in an abrasive, the particles on the surface of the coating agent layer can be dissolved and removed by polishing to form pores. Therefore, the particles are not particularly limited to hollow particles.

As the hollow particles, it is preferable to use silica balloons which can be polished with a general silica abrasive.
A silica balloon is a silica particle that is spherical silica and has a hollow interior (shell only).

As described above, the hollow particles are added to the coating agent to coat the surface of the work holding plate main body, and the surface of the coating agent layer is polished to remove the shell portion of the hollow particles by polishing. It is possible to easily form pores on the work holding surface of the work holding plate.

As another aspect of the work holding plate of the present invention, it is also preferable that the work holding surface of the work holding plate is pasted with a resin film containing particles which can be dissolved in a dissolving agent such as water or a solvent. Can be used.

As described above, the resin coated on the surface of the work holding plate body or the resin film adhered to the work holding surface is added with particles that can be dissolved by a dissolving agent such as water or a solvent, or hollow particles. Is added to perform a polishing treatment,
A coating agent layer surface or resin film surface having micropores is formed, and the surface having these micropores is used as a work holding surface. The micropores mean that the surface holding the wafer has a recess having a diameter of about 0.5 mm or less.

In the work holding plate of the present invention, the surface of the work holding plate main body is coated with a coating agent containing particles soluble in a dissolving agent such as water or a solvent, and only the particles on the surface portion of the coating agent layer are coated. When dissolving and removing to form pores on the surface of the coating agent layer and using the coating agent layer surface with the pores as the work holding surface, the surface of the work holding plate body that has been flattened by machining etc. It is possible to form pores only on the surface portion of the coating agent layer, that is, the work holding surface without impairing the flatness. In addition, when the surface of the work holding plate body is coated with a coating agent in which particles that can be dissolved in the polishing agent or hollow particles that can be removed by polishing are coated and the surface of the coating agent layer is subjected to polishing treatment, It is possible to form micropores on the surface of the coating agent layer, that is, on the work holding surface of the work holding plate, without impairing the flatness of the surface of the work holding plate main body as the particles on the surface are dissolved and pores are formed naturally. It will be possible. When the work holding plate is manufactured by such a method, the size and depth of the pores on the holding surface, the in-plane distribution, and the like can be formed appropriately.

The work polishing apparatus of the present invention is characterized by having the above-mentioned work holding plate of the present invention.

The polishing method of the present invention is a polishing method in which one main surface of a work is held and the other main surface is mirror-polished, and the work is held with micropores formed on the work holding surface of the work holding plate. And polishing. Particularly, it is preferable to use the work holding plate and the polishing device described above.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Various modifications and changes other than the illustrated examples are possible without departing from the technical idea of the present invention. Needless to say. The basic form of the polishing apparatus to which the technical idea of the present invention is applied is not particularly limited, but in the illustrated example described below, a single wafer is used for vacuum suction holding and polishing one wafer at a time on a wafer holding plate. A case where the technical idea of the present invention is applied to a system will be described.

FIG. 1 is a schematic cross-sectional explanatory view for explaining the outline of the structure of a polishing apparatus according to the present invention, which comprises a polishing head equipped with a work holding plate according to the present invention. As shown in FIG. 1, the polishing apparatus 10 of the present invention is configured to
Configured as a device for polishing one side of a semiconductor wafer,
The polishing apparatus 10 includes a rotating surface plate (rotary table) 12
And a polishing work holding plate 16 mounted on the polishing head 14 and an abrasive supply nozzle 18. A polishing cloth 20 is attached to the upper surface of the polishing platen 12. The polishing platen 12 is rotated by a rotating shaft 22 at a predetermined rotation speed.

The work holding plate 16 holds the work (wafer) W on its work holding surface 24 by vacuum suction or the like, and is mounted on the polishing head 14 having a rotating shaft 26.
The work W is pressed against the polishing cloth 20 with a predetermined load while being rotated by the polishing head 14. The polishing agent L is supplied from the polishing agent supply nozzle 18 onto the polishing cloth 20 at a predetermined flow rate, and the polishing agent L is supplied between the work W and the polishing cloth 20 to polish the work W.

Further, as shown in FIG. 1, the polishing work holding plate 16 of the present invention has a work holding plate body 16a having a work holding surface 24 and a number of through holes 28 for vacuum suction.
And a work holding board back plate 30. The through hole 28 is formed by the work holding board body 16a and the work holding board back plate 30.
The vacuum passage 34 is connected to a vacuum device (not shown) through a space 32 between the two, and a work W is sucked and held on the work holding surface 24 by the generation of a vacuum.

In particular, the surface 23 of the work holding board body 16a
Is coated with a coating agent layer 25 having a through hole 28, for example, a resin layer. This is because when the work W is directly held on the surface of the work holding plate body 16a made of metal, ceramics or the like, the back surface of the work W is scratched or soiled.
As the coating agent layer 25 on the surface 23 a of several tens of μm
The surface of the work-holding board body 16a is coated with a material such as a material known to have an ultra-thin Teflon (R) or nylon of a few millimeters, a resin layer such as vinyl chloride, or an acrylic resin plate with holes for vacuum suction. The work holding surface 24 is, for example, one that adheres to 23 and that acts as a suction plate surface whose surface is polished. Further, as the material used as the coating agent layer 25 for coating the surface 23 of the work holding plate body 16a, an epoxy resin which is a thermosetting resin is easy to coat, and the hardness and mechanical properties which are physical properties of the film after thermosetting. It is particularly useful in terms of quality such as strength and coefficient of linear expansion.

In addition, in the case of polishing, since a soft polishing cloth is used, even if the surface 23 of the work holding plate body 16a is finished flat, the surface of the polishing cloth 20 will be damaged due to creep deformation of the polishing cloth 20 or the like. Since the work gradually changes, there is a problem that the work after processing is not always flat. Therefore, by polishing the surface 23 of the work holding plate body 16a with a thin resin and then polishing the surface of the work holding plate body 16a, the polishing cloth 2
There is also a method in which the work holding plate main body 16a that follows the creep deformation of 0 is built in and then the work W is polished.

The polishing head 14 has a pressurizing space 38 inside the outer cover (rotary holder) 36 thereof, and holds the work holding plate 16 in an airtight manner via an elastic ring 39. The pressure space 38 is connected to an air compressor (not shown) via a pressure passage 40. Then, the work W is rotated or oscillated on the work holding surface 24, that is, the work holding board 16 that is vacuum-adsorbed and held on the surface of the coating agent layer 25, and at the same time, the back surface of the work holding board 16 is pressurized by air. The work holding plate 16 is pressed against the polishing cloth 20. In addition, in FIG. 1, 41 is a top ring.

As shown in FIG. 2, the work holding plate 16 of the present invention has a structure in which the surface 23 of the work holding plate main body 16a is coated with a coating agent layer 25 such as an epoxy resin. Particle) (or hollow particle) 42 that can be dissolved by a solubilizer such as water or a solvent. The size of the particles 42 is 3 to 3 for both particles and hollow particles that can be dissolved by water, a solvent, or the like.
It is a solid substance of about 300 μm. Examples of the material of the soluble particles include EDTA. Besides,
Water-soluble cellulose particles or the like can be used. This coating agent, that is, the particles 42 on the surface of the coating agent layer 25 is dissolved by a dissolving agent such as water or a solvent to form pores 44 on the surface of the coating agent layer 25, that is, the work holding surface 24 of the work holding plate 16. To do. An overall view of the work holding surface 24 of the work holding board 16 is shown in FIG. 3, and a schematic view in which a part thereof is enlarged is shown in FIG.

As the hollow particles, hollow particles having a thin shell can be used, and silica balloons of about 2 to 300 μm are particularly suitable. The pores 44 can be formed on the surface of the coating agent layer 25, that is, the work holding surface 24 of the work holding plate 16, by polishing the coating agent layer 25 including the hollow particles 42, for example, the resin layer. (FIGS. 3 and 4).

The diameter of the above-mentioned pores 44 is preferably 0.5 mm or less. This is because if it is larger than 0.5 mm, the shape of the pore may be transferred to the wafer surface. In addition, when the pores are formed by using particles that can be dissolved by the dissolving agent as described above, various pore diameters of about several μm to several hundreds of μm are formed. Therefore, the lower limit is not particularly limited, but if the pores are too small, water or air does not escape between the wafer and the work holding board when the wafer is adsorbed, and the air pool or water remains in the wafer and work holding board. Since there is a case in which the microtopography is generated and the nanotopography is aggravated, the work holding plate in a state in which many pores of 0.02 mm or more are formed is preferable. Particularly, it is preferable that the average pore diameter when evaluated in a certain area is several tens of μm or more on average, for example, the average pore diameter is 50 to 150 μm.

An example of the method for manufacturing the work holding plate of the present invention will be described. First, in step (a), a thermosetting resin and particles (or hollow particles) that can be dissolved in water or a solvent are charged into a stirring and mixing tank and sufficiently degassed under vacuum to remove air. In the step (b), the work holding plate body 16a of the work holding plate 16 is placed on the resin coating jig with the surface 23 facing upward, and the coating amount adjusting plate is set, and then the work holding plate body 1 is placed.
A thermosetting resin is poured on the surface 23 of 6a.

In step (c), a bar is slid on the coating amount adjusting plate to scrape off excess resin to form a resin layer having a uniform thickness. Next, in step (d), the work holding board body 16a coated with the resin is set in an electric heating furnace together with the resin coating jig, and heated gas is sent from below the resin coating jig to feed the work holding board body 16a. Heating is started while passing through the through hole 28, and the entire resin layer 25 is thermoset. In this case, after the resin in the peripheral portion of the through hole 28 is pre-cured, the remaining resin can be thermally cured. First, the resin in the peripheral portion of the through hole 28 is cured first. Blocking prevention can be made even more reliable. The temperature of the gas for thermosetting can be the same as or higher than the thermosetting temperature of the resin, but if it is the same as the thermosetting temperature of the resin, the thermosetting reaction rate of the resin depends on the heating of the resin. Since the rate becomes lower than the viscosity decreasing rate, the resin layer 25 can be formed without blocking the through holes 28, which is preferable.

By doing so, it is possible to manufacture the work holding plate body 16a in which the resin layer 25 on the surface 23 of the work holding plate body 16a is added with particles or hollow particles which can be dissolved by water or a solvent.

Next, in the step (e), the work holding plate body 16a whose surface is coated with the resin layer 25 is set on the lapping machine, and the lapping liquid is dropped from the nozzle while the platen is rotated to drop the resin layer 25. The surface is ground, the surface is corrected, and sufficiently washed in step (f).

Further, in the step (g), the work holding plate body 16a whose surface is covered with the resin layer 25 which has been subjected to the lapping correction is set in the polishing apparatus, and the polishing agent is dropped from the nozzle while rotating the surface plate to make the resin. The surface of the layer 25 is polished to correct the surface, sufficiently washed to complete the work holding plate body 16a, and the work holding plate back plate 30 is attached to the work holding plate main body 16a to manufacture the polishing head 14. By doing so, the work holding plate 16 in which the micropores 44 are formed on the work holding surface 24 of the work holding plate body 16a is obtained (FIGS. 3 and 4).

Next, an example in which the technical idea of the present invention is applied to a wax-free polishing type polishing apparatus will be described with reference to the examples shown in FIGS. In FIG. 5, reference numeral 17 denotes a work holding board, the back surface of which is attached to the top ring 41 and the work holding board body 17a and the work holding board body 1
It has a resin film 25a attached to the surface 23a of 7a by a double-sided tape or an adhesive.

As shown in FIG. 6, the resin film 25a
When molding, the resin block is formed by adding particles that can be dissolved with a solvent or a dissolving agent such as water into the raw material resin, then sliced into thin pieces and ground by machining to flatten the surface. It is possible to form the pores 44 only on the surface of the resin film 25a by attaching the film 25a to the work holding plate body 17a with an adhesive and treating the surface of the resin film 25a with a dissolving agent such as water or a solvent. You can
The surface of the resin film 25a on which the pores 44 are formed can also be used as the work holding surface 24. In FIGS. 5 and 6, reference numeral 46 denotes a template provided to prevent the wafer from falling off during polishing. The other configuration is the same as that of FIG. 1, and thus the repetitive description is omitted. Note that, in the examples of FIGS. 5 and 6, unlike the examples of FIGS. 1 and 2, the case where the through hole 28 for vacuum suction is not provided in the work holding plate body 17a is shown. The work W is formed on the holding board body 17a and the work W is held on the work holding surface 2
It goes without saying that a structure of adsorbing and holding to No. 4 can be adopted.

[0041]

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(Embodiment 1) An example of a method for manufacturing a work holding plate of the present invention will be described. First, a thermosetting epoxy resin as a thermosetting resin and EDTA having a particle size of about 3 to 300 μm as particles that can be dissolved in water or a solvent are charged into a stirring and mixing tank at a ratio of 20% by weight with respect to the epoxy resin, and sufficiently defoamed under vacuum. To remove air. A silicon carbide (SiC) perforated plate with a thickness of 30 mm (pore diameter 0.4
mm; thermal expansion coefficient 4 × 10 ^-6 / ° C), place the work holding board body with the work holding surface facing up, set the coating amount adjustment plate, and then set the thermosetting resin on the work holding surface. Pour.

A bar is slid on the coating amount adjusting plate to scrape off excess resin to form a resin layer having a thickness of about 1 mm. Then, the work holding board body coated with resin is placed in an electric heating furnace together with the resin coating jig, and heated gas is sent from below the resin coating jig to heat it while passing through the through hole of the work holding board body. Then, the entire resin layer is thermally cured.

Next, the work holding plate main body coated with the resin layer is set on the lapping machine, the lapping liquid is dropped from the nozzle while the platen is rotated, the surface of the resin layer is ground and the surface is repaired and thoroughly washed. To do. Furthermore, set the work holding plate body covered with the resin layer that has finished the wrapping correction in the polishing device, and while the surface plate is rotating, drop the abrasive from the nozzle to polish the surface of the resin layer and correct the surface (approx. 40μ
m polishing) and sufficiently washed to complete the work holding plate main body, and the back plate of the work holding plate was attached to this to prepare a polishing head.

By doing so, EDTA is dissolved during lapping and polishing, and a work holding plate having micropores formed on the surface of the work holding plate can be obtained. The pore diameter is
It existed in the size of several μm to several hundred μm, but almost 20 μm
It was not less than (0.02 mm) and not more than 500 μm (0.5 mm). In this embodiment, the center of the work holding plate is 1 cm.
^The average pore diameter (referred to as the average pore diameter) determined in the area ² was about 150 μm.

(Embodiment 2) Such a work holding plate is set in a polishing apparatus as shown in FIG. 1 to form a polishing head.

A silicon wafer (diameter 20
A wafer having a thickness of 0 mm and a thickness of 735 μm) was polished. Polishing load 30 kPa and relative polishing speed 5 as work polishing conditions
It was carried out at 0 m / min and a target polishing margin of 10 μm. A non-woven polishing cloth was used as the polishing cloth, and an alkaline solution (pH 10.5) containing colloidal silica was used as the polishing agent.

The flatness, waviness and nanotopography of the work after polishing were confirmed. The flatness is 2 mm around the circumference with a capacitance type thickness gauge (Ultra Gauge 9700 manufactured by ADE).
The measurement was performed under the exclusion condition, and the waviness of the work surface was observed with a magic mirror. Nanotopography is Nano made by ADE
It was measured with a mapper under a measurement condition of 2 mm square.

As a result, the flatness of the work is determined by SBIRmax (Site Back-side Ide) based on the back surface.
al Range: SEMI (Semiconductor)
or Equipment and Material
s International) value standardized by M1 etc., cell size 25 × 25) 0.15 μm
A high flatness was achieved. In addition, no waviness was observed on the surface of the work even with a magic mirror, and high-precision machining was achieved. Furthermore, the value of nanotopography was as good as 10 nm.

(Comparative Example 1) A work holding plate was formed in the same manner as in Example 1 without adding EDTA to the epoxy resin layer of the work holding plate, and then polished in the same manner as in Example 2.

As a result, as for the flatness of the work, a high flatness of 0.15 μm in SBIRmax based on the back surface is achieved,
Even with a magic mirror, no undulations were seen on the work surface, and high-precision machining was achieved. However, the value of nanotopography was about 30 nm due to the generation of many micro-dimples which are considered to be caused by the accumulation of air.

(Example 3) Particle size of about 1 in epoxy resin
Example 1 was filled with 20% by weight of hollow silica particles of 5 μm.
A work holding plate was prepared in the same manner as in. As a result, a work holding plate having an average pore diameter of about 20 μm was obtained. Using this work holding plate, the wafer was polished in the same manner as in Example 2, and the flatness of the wafer was confirmed. As a result SBI
Rmax was 0.14 μm. The nanotopography level was as good as 18 nm.

(Comparative Example 2) A work holding plate was prepared in the same manner as in Example 1 by kneading the epoxy resin under pressure and introducing air bubbles. As a result, a work holding plate having an average pore diameter of 600 μm was obtained. Using this work holding plate, the wafer was polished in the same manner as in Example 2, and the flatness of the wafer was confirmed. As a result, SBIRmax was 0.16 μm.
The nanotopography level was deteriorated to 50 nm due to the formation of protrusions at the portions considered to correspond to the large pores.

The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, has substantially the same configuration as the technical idea described in the scope of the claims of the present invention, and has any similar effect to the present invention. It is included in the technical scope of the invention.

For example, in the present embodiment, the particles are added to the epoxy resin, but particles soluble in water or a solvent may be added to the resin film made of urethane or the like. With a resin film such as urethane, it is possible to form pores with a foaming agent, but if the pores are formed by adding particles of a fixed particle size as in the present invention and then melting or polishing it, the size can be increased. , Depth and in-plane distribution can be arbitrarily formed, which is preferable.

[0056]

The typical effects achieved by the present invention will be described. First, there is provided a polishing work holding plate capable of obtaining a highly accurate work surface. Therefore, by using this, a work having an excellent flatness and a waviness-free surface can be produced by polishing. In particular, unevenness at the nanotopography level can be improved, and in the case of a semiconductor wafer polished by using the polishing work holding plate of the present invention, it is possible to reduce focus defects in lithography exposure in the highly integrated device process, The yield of integrated devices can be improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional explanatory view showing one embodiment of a polishing apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional explanatory view showing a main part of the work holding plate of FIG.

3 is an explanatory view showing a work holding surface of the work holding plate of FIG. 2. FIG.

FIG. 4 is an enlarged view of part A of FIG.

FIG. 5 is a schematic cross-sectional explanatory view showing another embodiment of the polishing apparatus according to the present invention.

6 is a schematic cross-sectional explanatory view showing a main part of the work holding plate of FIG.

[Explanation of symbols]

10, 11: polishing device, 12: surface plate, 14: polishing head, 16, 17: work holding plate, 16a: work holding plate body, 18: abrasive supply nozzle, 20: polishing cloth, 22:
Rotating shaft, 23: surface of work holding plate body, 24: work holding surface, 25: coating agent layer, 26: rotating shaft, 2
8: Through hole, 30: Work holding plate back plate, 32: Space part,
34: vacuum path, 36: outer cover (rotary holder),
38: pressurized space, 39: elastic ring, 40: pressurized passage, 42: particles or hollow particles, 44: pores.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Fumio Suzuki             Odaira, Odakura, Saigo Village, Nishishirakawa-gun, Fukushima Prefecture             No. 150 Shin-Etsu Semiconductor Co., Ltd. Semiconductor Shirakawa             In the laboratory F-term (reference) 3C058 AA07 AB04 CB01 DA17

Claims (12)

[Claims] 1. A work holding plate having a work holding plate body for holding one main surface of a work and mirror-polishing the other main surface, wherein micropores are formed on the work holding surface of the work holding plate. Work holding board characterized by that. 2. The work holding plate according to claim 1, wherein a pore diameter formed on the work holding surface of the work holding plate is 0.5 mm or less. 3. The work holding plate according to claim 1, wherein the surface of the organic or inorganic coating agent layer coating the surface of the work holding plate body is used as a work holding surface of the work holding plate. . 4. Particles that can be dissolved by a dissolving agent are added to the coating agent, and the particles on the surface of the coating agent layer are dissolved by the dissolving agent to form pores on the work holding surface of the work holding plate. The work holding board according to claim 3, wherein 5. Particles capable of forming pores are added to a work holding surface of the work holding plate by subjecting the coating material layer to a polishing treatment, and the coating agent layer surface is subjected to a polishing treatment to obtain the work holding plate. The work holding plate according to claim 3, wherein a pore is formed on the work holding surface. 6. The work holding plate according to claim 4, wherein the particles that can be dissolved by the dissolving agent are EDTA or water-soluble cellulose particles. 7. The particles capable of forming pores on the surface thereof by the polishing treatment are hollow particles.
Work holding plate described. 8. The work holding plate according to claim 7, wherein the hollow particles are silica balloons. 9. A work holding surface of the work holding plate is adhered with a resin film containing particles that are soluble in a dissolving agent, and the particles on the surface of the resin film are dissolved by the dissolving agent to hold the work of the work holding plate. The work holding plate according to claim 1 or 2, wherein pores are formed on the surface. 10. The work holding plate according to claim 4, wherein the solubilizer is water or a solvent. 11. A polishing apparatus for a work, comprising the work holding plate according to any one of claims 1 to 10. 12. A polishing method in which one main surface of a work is held and the other main surface is mirror-polished, in which the work is held and polished with micropores formed on the work holding surface of the work holding plate. Characteristic polishing method.