JP2018051702A - Polishing pad holding surface plate, substrate polishing device and polishing pad holding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing pad holding surface plate, a substrate polishing device and a polishing pad holding method, which allow a polishing pad to be easily and stably held and allow air bubble to be surely removed from a space between the polishing pad and a surface plate main body.SOLUTION: A substrate polishing device 200, which polishes a wafer W by slidably contacting the wafer W to a polishing pad P, comprises a surface plate main body 32 formed of a three-dimensional porous body and a decompressing pump 34; and further comprises a polishing pad holding surface plate 30 in which the decompressing pump 34 decompresses the surface plate main body 32 so that the polishing pad P is adsorbed and held on a polishing side surface 32P of the surface plate main body 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a polishing pad holding surface plate, a substrate polishing apparatus, and a polishing pad holding method for holding a polishing pad when polishing a substrate such as a wafer.

  As is well known, in a substrate polishing apparatus that polishes a substrate such as a wafer, it is widely practiced to polish the substrate by pressing and relatively moving the substrate against a polishing pad attached to a surface plate ( For example, see Patent Document 1.)

In such a polishing apparatus, in order to ensure the polishing quality of the substrate, it is necessary to arrange the polishing pad flat on the surface plate body and ensure the flatness according to the polishing quality of the substrate on the polishing pad. .
Various techniques for efficiently holding the polishing pad on the surface plate body have been disclosed (see, for example, Patent Document 2).

JP-A-9-155721 JP 2004-259814 A

  However, when sticking the polishing pad to the polishing pad holding surface plate, small bubbles may enter between the polishing pad and the surface plate body, and if bubbles enter between the polishing pad and the surface plate, the polishing pad Concavities and convexities are formed on the substrate, and the polishing quality of the substrate is remarkably lowered, making it difficult to ensure sufficient polishing quality.

Therefore, great care is taken when attaching the polishing pad to the polishing pad holding surface plate.
In addition, when air bubbles enter between the polishing pad and the surface plate, a lot of time is spent on removing the air bubbles, but the air bubbles that have entered between the polishing pad and the surface plate must be reliably removed. Is not easy.

  Therefore, it is possible to hold the polishing pad easily and stably on the polishing pad holding surface plate, and the polishing pad is uneven by removing air bubbles reliably between the polishing pad and the surface plate body. There is a need for a technique to suppress this and ensure sufficient polishing quality.

  The present invention has been made in view of such problems, and is used in a polishing apparatus for polishing a substrate such as a wafer, and can easily and stably hold a polishing pad. An object of the present invention is to provide a polishing pad holding surface plate, a substrate polishing apparatus, and a polishing pad holding method capable of reliably removing air bubbles from between the main body and the surface plate body.

In order to solve the above problems, the present invention proposes the following means.
The invention according to claim 1 is a polishing pad holding surface plate that is capable of holding a polishing pad and is used for polishing the substrate by pressing and relative movement of the substrate against the polishing pad, and a three-dimensional porous body And a pressure reducing means, and the pressure reducing means depressurizes the surface plate main body to reduce the polishing on the polishing pad holding surface. The pad is configured to be sucked and held.

The polishing pad holding surface plate according to the present invention includes a surface plate body formed of a three-dimensional porous body and having a polishing pad holding surface, and a decompression means, and the decompression means decompresses the surface plate body. Since the polishing pad is sucked and held on the polishing pad holding surface, the polishing pad can be easily and stably held and air bubbles can be reliably removed from between the polishing pad and the surface plate body. It is possible to suppress the occurrence of irregularities due to bubbles on the surface of the polishing pad, and to ensure stable flatness in the polishing pad.
As a result, it is possible to stably ensure the polishing quality of the substrate and efficiently improve the productivity related to substrate polishing.

In this specification, the three-dimensional porous body refers to a three-dimensional network structure in which a large number of holes are opened on the surface, and fluid (air or the like) can flow in any direction by voids formed inside. . In addition, the three-dimensional network structure may have regularity formed on the base material forming the voids or the three-dimensional network structure in addition to the voids irregularly formed, such as sponge or sponge.
Further, for example, when a fluid (for example, air) in the platen body is sucked (depressurized) from a suction part formed in a specific part, a predetermined part (for example, a specific surface or a suction part is excluded) Even when fluid flows in from the entire surface, it is preferable that the inside of the surface plate body can be maintained in a decompressed state.

  Further, in this specification, reducing the pressure of the surface plate body means that an adsorbing force is generated on the polishing pad holding surface when a fluid such as air flows in the surface plate body, and the fluid in the surface plate body is negative pressure. This means that an adsorption force is generated on the polishing pad holding surface.

  A second aspect of the present invention is the polishing pad holding surface plate according to the first aspect, wherein the three-dimensional porous body is a porous ceramic.

According to the polishing pad holding surface plate of the present invention, since the three-dimensional porous body is porous ceramics, it is possible to stably deform the substrate while suppressing deformation due to polishing pressure or the like.
In addition, it is possible to suppress the wear and deterioration of the surface plate body due to secular change, and to ensure stable polishing quality over a long period of time.

  The invention according to claim 3 is the polishing pad holding surface plate according to claim 1 or 2, wherein the polishing pad holding surface plate is disposed on a connecting surface located on the opposite side of the polishing pad holding surface of the surface plate body. A platen support table for supporting the plate body is provided, wherein the pressure reducing means is configured to depressurize the platen body through a pressure reducing fluid channel formed in the platen table support. To do.

  According to the substrate polishing apparatus of the present invention, the surface plate support table is provided on the connection surface of the surface plate body, and the pressure reducing means is provided via the pressure reducing fluid channel formed in the surface plate support table. Since the main body is configured to depressurize, the surface plate main body can be efficiently depressurized with a simple configuration.

  The invention according to claim 4 is the polishing pad holding surface plate according to claim 3, further comprising cooling water supply means for cooling the surface plate body, wherein the surface plate support has a reduced pressure air flow path. A pressure reducing portion formed and connected to the pressure reducing means; and a surface plate cooling member formed with a cooling water flow path and connected to the cooling water supply means, wherein the pressure reducing portion and the surface plate cooling member are connected to the connection surface. Are arranged in this order.

  According to the polishing pad holding surface plate according to the present invention, the surface plate main body is provided with a cooling water supply means for cooling the surface plate body. Since the water flow path is formed and the surface plate cooling member connected to the cooling water supply means is provided, and the pressure reducing portion and the surface plate cooling member are arranged in this order from the connection surface, the surface plate body is cooled and efficiently The pressure can be reduced.

  The invention according to claim 5 is the polishing pad holding surface plate according to claim 3, further comprising a cooling water supply means for cooling the surface plate body, wherein the surface plate support is formed with a cooling water flow path. And a platen cooling member connected to the cooling water supply means, wherein the pressure reducing means is provided in the cooling water supply means and sucks the cooling water in the cooling water flow path so that the inside of the platen main body is drawn. It is characterized by comprising a cooling water pump that depressurizes.

  According to the polishing pad holding surface plate according to the present invention, the surface plate cooling member is provided with a cooling water supply means for cooling the surface plate body, and the surface plate support is formed with a cooling water flow path and connected to the cooling water supply means. The pressure reducing means is constituted by a cooling water pump provided in the cooling water supply means for reducing the pressure inside the surface plate body by sucking the cooling water in the cooling water flow path, so that the surface plate has a simple structure. The main body can be decompressed and cooled efficiently.

  The invention according to claim 6 is a substrate polishing apparatus, wherein the polishing pad holding surface plate according to any one of claims 1 to 5 and the substrate are held and orthogonal to the surface to be polished of the substrate. And a polishing unit having a substrate holding platen that is rotatable around an axis line and a substrate holding platen pressing unit that presses the substrate against the polishing pad.

According to the substrate polishing apparatus of the present invention, bubbles remaining between the polishing pad and the surface plate main body can be easily and efficiently removed to stably hold the polishing pad and rotate the substrate while rotating the substrate. Can be pressed and polished.
As a result, it is possible to stably ensure the polishing quality of the substrate and efficiently improve the productivity related to substrate polishing.

  The invention described in claim 7 is a substrate polishing apparatus, comprising two polishing pad holding surface plates according to any one of claims 1 to 5, wherein the polishing pad holding surface plates are polished with each other. A pad holding surface is arranged to be opposed to be able to press the substrate, and at least one of them is rotated so that the polishing pad and the substrate can be moved relative to each other.

According to the substrate polishing apparatus of the present invention, bubbles remain between the polishing pad and the surface plate body easily and efficiently to stably hold the polishing pad, and between the polishing pads arranged opposite to each other. Thus, both surfaces of the substrate can be efficiently polished.
As a result, it is possible to stably ensure the polishing quality of the substrate and efficiently improve the productivity related to substrate polishing.

  The invention according to claim 8 is a polishing plate holding method in a surface plate holding a polishing pad and a substrate polishing apparatus in which a substrate can be pressed against and relative to the polishing pad, and the surface plate is a three-dimensional porous plate. A polishing pad holding surface formed by a material and capable of holding the polishing pad, and the three-dimensional porous body portion of the surface plate is depressurized by a pressure reducing means to adsorb the polishing pad to the holding surface It is characterized by holding.

According to the polishing pad holding method according to the present invention, the surface plate is formed of a three-dimensional porous body, has a polishing pad holding surface capable of holding the polishing pad, and the three-dimensional porous body portion of the surface plate Since the polishing pad is sucked and held on the holding surface by reducing the pressure by the pressure reducing means, the polishing pad can be easily and stably held, and air bubbles can be reliably removed from between the polishing pad and the surface plate body. Further, it is possible to suppress the occurrence of irregularities due to bubbles on the surface of the polishing pad, and to ensure stable flatness in the polishing pad.
As a result, it is possible to stably ensure the polishing quality of the substrate and efficiently improve the productivity related to substrate polishing.

According to the polishing pad holding surface plate, the substrate polishing apparatus, and the polishing pad holding method according to the present invention, the polishing pad is easily and stably held on the surface plate body, and air bubbles are generated between the polishing pad and the surface plate body. It can be removed reliably.
As a result, it is possible to stably ensure the polishing quality of the substrate and efficiently improve the productivity related to substrate polishing.

It is a fragmentary longitudinal cross-sectional view explaining schematic structure of the substrate polishing apparatus which concerns on 1st Embodiment of this invention, and is a figure shown by arrow II in FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining schematic structure of the substrate polishing apparatus which concerns on 1st Embodiment of this invention, and is a cross-sectional view shown by arrow II-II in FIG. It is a fragmentary longitudinal cross-sectional view explaining schematic structure of the substrate polishing apparatus which concerns on 2nd Embodiment of this invention, and is a figure shown by arrow III-III in FIG. It is a top view explaining schematic structure of the substrate polish device concerning a 2nd embodiment of the present invention. It is a figure explaining schematic structure of the substrate polishing apparatus which concerns on 2nd Embodiment of this invention, and is a cross-sectional view shown by arrow VV in FIG. It is a figure explaining schematic structure of the board | substrate polish apparatus which concerns on 2nd Embodiment of this invention, and is a cross-sectional view shown by arrow VI-VI in FIG. It is a fragmentary longitudinal cross-sectional view explaining schematic structure of the substrate polishing apparatus which concerns on 3rd Embodiment of this invention, and is a figure shown by arrow III-III in FIG. It is a figure explaining schematic structure of the board | substrate polish apparatus which concerns on 3rd Embodiment of this invention, and is a cross-sectional view shown by arrow VIII-VIII in FIG. It is a conceptual diagram explaining schematic structure of the substrate polishing apparatus which concerns on 4th Embodiment of this invention.

<First Embodiment>
Hereinafter, a schematic configuration of the substrate polishing apparatus and the polishing pad holding method according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial longitudinal sectional view illustrating a schematic configuration of a substrate polishing apparatus according to a first embodiment of the present invention, and FIG. 2 is a transverse sectional view illustrating a schematic configuration of the substrate polishing apparatus.
1 and 2, reference numeral 100 denotes a substrate polishing apparatus, reference numeral 10 denotes a polishing pad holding surface plate, reference numeral W denotes a wafer (substrate), and reference numeral P denotes a polishing pad.

For example, as shown in FIG. 1, the substrate polishing apparatus 100 includes a polishing pad holding surface plate 10 and a polishing unit 20.
Then, while the polishing unit 20 and the polishing pad holding surface plate 10 are moved relative to each other, the wafer (substrate) W is pressed against and slidably contacted with the polishing pad P to polish the wafer W.

  As shown in FIG. 1, the polishing pad holding surface plate 10 includes, for example, a surface plate support 11, a surface plate body 12, a cooling water supply device 13, and a pressure reducing pump (pressure reducing means) 14. The polishing pad P is adsorbed and held on the polishing pad holding surface 12P located on the upper surface of the surface plate body 12.

In this embodiment, the cooling water supply device 13 includes a cooling water pump 13P and a cooling device 13S, and the cooling water pump 13P transfers the sucked cooling water C to the cooling device 13S. .
The decompression pump 14 can employ various decompression means that can suck air, such as a vacuum pump.

  The surface plate support 11 includes a surface plate support main body 11A and a surface plate cooling member 11B that is disposed on the upper surface of the surface plate support main body 11A and connected to the lower surface of the surface plate main body 12.

  The surface plate support base body 11A is made of, for example, a stainless steel formed in a rectangular parallelepiped, and supports the surface plate body 12 via a surface plate cooling member 11B that is installed on the floor and disposed above. Yes.

  As shown in FIGS. 1 and 2, the surface plate cooling member 11B is made of, for example, a flat plate-shaped stainless steel, and is formed with a cooling water flow path (cooling medium flow path) 11U and a decompression air suction hole 11H. Has been.

  The cooling water flow path (cooling medium flow path) 11U is constituted by a two-dimensionally expanding recess formed on the upper surface of the surface plate cooling member 11B to absorb the heat generated during polishing by circulating the cooling water, The temperature of the polishing pad P and the wafer W is prevented from rising during polishing.

  In this embodiment, the cooling water flow path 11U extends, for example, from the first side (the lower side in FIG. 2) of the platen cooling member 11B having a rectangular shape in plan view toward the second side facing the first side. Two substantially U-shaped grooves that fold back to the first side before reaching the second side, and a substantially U-shaped connecting portion that connects adjacent sides of the two grooves, The grooves of the mold are opened on the first side on the sides separated from each other to constitute the cooling water inlet 111U and the cooling water outlet 112U.

  The cooling water inlet 111U is connected to the cooling water supply device 13 via the cooling water supply path 13A, so that the cooling water is supplied to the cooling water inlet 111U via the cooling water supply path 13A and flows through the cooling water flow path 11U. It has become.

  The cooling water outlet 112U is connected to the cooling water supply device 13 via the cooling water recirculation path 13B, and the cooling water flowing through the cooling water flow path 11U is sucked from the cooling water outlet 112U by the cooling water pump 13P, and the cooling water recirculation path The refrigerant flows back to the cooling device 13S through 13B.

  The decompression air suction hole 11H is formed, for example, from the suction side opening 111H that opens at a position avoiding the cooling water flow path 11U on the upper surface of the surface plate cooling member 11B toward the decompression pump connection port 112H that opens to the lower surface side. .

  The decompression pump connection port 112H is connected to the decompression pump 14 via the decompression air suction line 14L. By operating the decompression pump 14, the suction side opening 111H side is evacuated and the platen body 12 The internal pressure is reduced.

The surface plate main body 12 is formed of, for example, a three-dimensional porous body made of porous ceramics.
The three-dimensional porous body has, for example, a sponge-like three-dimensional network structure, and air can flow through the inside of the surface plate body 12 in an arbitrary direction through the gap formed in the three-dimensional network structure. Has been. Whether the three-dimensional network structure has regularity or irregularity can be arbitrarily set.

In this embodiment, for example, porous ceramics made of alumina (Al ₂ O ₃ ) -based ceramics are used as the three-dimensional porous body.
The porous ceramics preferably has, for example, a thermal expansion coefficient (linear expansion coefficient) of 1 to 5 × 10 ⁻⁶ / K, a porosity of about 40%, and an average pore diameter of about 20 μm.

  With such a configuration, when the surface plate body 12 is depressurized through the suction side opening 111H that opens to the upper surface of the surface plate cooling member 11B with the polishing pad P adsorbed to the polishing pad holding surface 12P, Even if air is sucked from the four side surfaces excluding the lower surface of the surface plate body 12, the reduced pressure state in the surface plate body 12 can be maintained while the polishing pad P can be held without sealing the four side surfaces. The polishing pad P can be stably held on the polishing pad holding surface 12P.

  Instead of the cooling water supply device 13, various well-known cooling water supply means such as a form for circulating the cooling water C and a form for discharging the supplied cooling water C to the outside (for example, tap water) are used. Is possible.

  The polishing unit 20 includes, for example, a substrate holding surface plate 21, a substrate holding surface plate pressing portion 22, and a substrate holding surface plate driving motor (not shown).

The substrate holding platen 21 can polish the wafer W by adsorbing and holding the wafer (substrate) W and sliding the wafer W on the polishing pad P, for example.
The substrate holding surface plate 21 is connected to a substrate holding surface plate drive motor (not shown), and is rotated in the direction of the arrow R1 around the rotation axis O1, for example, by the substrate holding surface plate drive motor. Thus, the wafer W is rotated with respect to the polishing pad P.

  In this embodiment, the substrate holding surface plate 21 is connected to, for example, XY direction driving means (not shown), and the substrate holding surface plate 21 and the polishing pad holding surface plate 10 are connected to the XY direction driving means (not shown). As shown in the figure, relative movement is possible along the horizontal plane in the direction of the arrow TX and the arrow TY.

  The substrate holding surface plate pressing unit 22 moves, for example, the substrate holding surface plate 21 in the up and down direction indicated by the arrow TZ, and contacts and separates the substrate holding surface plate 21 from the polishing pad P and presses it with a predetermined pressure. It is supposed to be.

  As a result, while the wafer W is rotated in the direction of the arrow R1, the polishing pad P is relatively moved in the directions of the arrow TX and the arrow TY, and the wafer W is pressed against the polishing pad P for polishing.

According to the substrate polishing apparatus 100 according to the first embodiment, the surface plate main body 12 is made of porous ceramics, and the surface plate main body 12 is depressurized by the vacuum pump 14 to reduce the polishing pad holding surface of the surface plate main body 12. Since the polishing pad P is adsorbed and held on 12P, the polishing pad P can be held easily and stably, and air bubbles can be reliably removed from between the polishing pad P and the surface plate body 12. .
As a result, it is possible to stably secure the polishing quality of the wafer W and improve the productivity when polishing the wafer W.

  In addition, according to the substrate polishing apparatus 100 and the polishing pad holding method according to the first embodiment, the surface plate body 12 is formed of porous ceramics, and the polishing pad P is sucked uniformly over the entire surface. Since it is held by suction, the polishing pad P can be held easily and stably.

In addition, according to the substrate polishing apparatus 100 and the polishing pad holding method according to the first embodiment, the surface plate body 12 is formed of porous ceramics, so that the surface plate body 12 is deformed by pressure or the like during polishing. It is suppressed.
Further, the surface plate body 12 is prevented from being altered, worn, or deteriorated due to secular change, and stable polishing quality can be ensured over a long period of time.

  In addition, according to the substrate polishing apparatus 100 and the polishing pad holding method according to the first embodiment, the surface plate body 12 is sucked through the pressure reducing air suction hole 11H opened on the upper surface of the surface plate cooling member 11B. The surface plate body 12 can be depressurized with a simple configuration.

Second Embodiment
Next, a schematic configuration of a substrate polishing apparatus according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a partial longitudinal sectional view illustrating a schematic configuration of a substrate polishing apparatus according to a second embodiment of the present invention, and FIG. 4 is a plan view illustrating a schematic configuration of the substrate polishing apparatus.
3 and 4, reference numeral 200 denotes a substrate polishing apparatus, reference numeral 30 denotes a polishing pad holding surface plate, reference numeral W denotes a wafer (substrate), and reference numeral P denotes a polishing pad.

For example, as shown in FIG. 3, the substrate polishing apparatus 200 includes a polishing pad holding surface plate 30 and a polishing unit 40.
While the wafer (substrate) W and the polishing pad holding surface plate 30 are moved relative to each other by the polishing unit 40, the wafer W can be polished by pressing and slidingly contacting the wafer W against the polishing pad P.

  As shown in FIG. 3, the polishing pad holding surface plate 30 includes, for example, a surface plate support 31, a surface plate body 32, a cooling water supply device 33, a decompression pump (decompression unit) 34, and a drive motor 35. The surface plate main body 32 holds the polishing pad P on the polishing pad holding surface 32P and can be rotated around the rotation axis O2 by the drive motor 35 in the direction of the arrow R2.

  Further, the surface plate support 31, the cooling water supply device 33, the surface plate support 31, and the decompression pump (pressure reduction means) 34 are connected by, for example, a rotary joint (not shown). It is possible to circulate the cooling water C while rotating it and suck the reduced-pressure air.

The cooling water supply device 33 includes, for example, a cooling water pump 33P and a cooling device 33S, and the cooling water pump 33P transfers the sucked cooling water C to the cooling device 33S.
The decompression pump (decompression unit) 34 is constituted by various vacuum pumps that can suck a substrate such as air, for example.

The surface plate support 31 has a circular outer shape, and includes a surface plate cooling member 311 and a surface plate decompression member 312.
The surface plate cooling member 311 and the surface plate decompression member 312 are arranged in this order from below, and the surface plate decompression member 312 is connected to the lower surface of the surface plate body 32 so as to support the surface plate body 32. It has become.

Hereinafter, the surface plate cooling member 311 will be described with reference to FIG. FIG. 5 is a diagram illustrating a schematic configuration of the surface plate cooling member 311 according to the second embodiment, and is a cross-sectional view taken along line V-V in FIG. 3.
As shown in FIG. 5, the platen cooling member 311 is made of, for example, stainless steel formed in a disk shape, and has two cooling water passages (cooling medium passages) 311 </ b> U formed of recesses on the upper surface. It is formed dimensionally, and the cooling water is circulated through the cooling water flow path 311U to absorb heat, thereby suppressing the temperature of the polishing pad P and the wafer W from rising during polishing.

In this embodiment, the cooling water flow path 311U is constituted by, for example, six blocks formed at intervals of 60 ° around the rotation axis O2.
Further, as shown in FIG. 5, each block constituting the cooling water flow path 311U includes a plurality of circumferential recesses extending in the circumferential direction of the surface plate cooling member 311 and the circumferential recesses from the outer peripheral side to the inner periphery. A plurality of radial recesses alternately connected in the radial direction at one end side and the other end side in the circumferential direction toward the side.

  The cooling water inlet 311A is connected to the cooling water supply device 33 via the cooling water supply path 33A, and the cooling water C supplied to the cooling water flow path 311U via the cooling water supply path 33A is the surface plate cooling member 311. It is designed to circulate two-dimensionally on the top surface.

The cooling water outlet 311B is connected to the cooling water supply device 33 via the cooling water recirculation path 33B, and the cooling water pump 33P sucks the cooling water C from the cooling water outlet 311B via the cooling water recirculation path 33B. Then, it is refluxed to the cooling device 33S.
As a result, the cooling water flowing in from the cooling water inlet 311A located on the outer peripheral side of the surface plate cooling member 311 flows smoothly in the circumferential direction and the radial direction toward the cooling water outlet 311B located on the inner peripheral side. It has become.

  Next, the platen decompression member 312 will be described with reference to FIG. FIG. 6 is a diagram illustrating a schematic configuration of the platen pressure reducing member 312 according to the second embodiment, and is a cross-sectional view taken along arrows VI-VI in FIG. 3.

  As shown in FIG. 6, the platen pressure reducing member 312 is made of, for example, stainless steel formed in a disc shape, and has a reduced pressure air flow path (reduced fluid flow path) 312U formed of a recess on the upper surface. It is formed two-dimensionally.

  In this embodiment, the reduced pressure air flow path (reduced fluid flow path) 312U is, for example, a circumferential recess in which recesses extending in the circumferential direction around the rotation axis O2 are formed in a plurality of stages at intervals in the radial direction. And between the circumferential recess on the outer peripheral side and the circumferential recess on the inner peripheral side at 90 ° intervals around the rotation axis O2, and with a one-step transition from the outer peripheral side to the inner peripheral side, it is shifted by 45 ° in the circumferential direction. And a plurality of radial recesses arranged.

  The reduced-pressure air suction port 312B is connected to the reduced-pressure pump (decompression means) 34 via the pressure-reduction line 34L, and sucks the reduced-pressure air from the lower surface of the surface plate body 32 via the reduced-pressure air suction port 312B. 32 is depressurized, and the polishing pad holding surface 32P of the surface plate body 32 is set to a negative pressure so that the polishing pad P is adsorbed and held on the polishing pad holding surface 32P.

  The surface plate body 32 includes, for example, a three-dimensional porous body made of porous ceramics whose outer shape is circular, and a frame body 32A formed so as to surround the outer periphery of the three-dimensional porous body. The three-dimensional porous body has, for example, a sponge-like three-dimensional network structure, and air can flow through the inside of the surface plate body 32 in any direction through the gap formed in the three-dimensional network structure. Has been. Whether the three-dimensional network structure has regularity or irregularity can be arbitrarily set.

In this embodiment, for example, porous ceramics made of alumina (Al ₂ O ₃ ) -based ceramics are used as the three-dimensional porous body.
The porous ceramics preferably has, for example, a thermal expansion coefficient (linear expansion coefficient) of 1 to 5 × 10 ⁻⁶ / K, a porosity of about 40%, and an average pore diameter of about 20 μm.

  With such a configuration, the air does not enter the surface plate main body 32 from the outer periphery of the surface plate main body 32 in a state where the polishing pad P is adsorbed to the polishing pad holding surface 32P. Thus, the reduced pressure state inside the surface plate body 32 can be efficiently maintained, and the polishing pad P can be efficiently and stably held on the polishing pad holding surface 32P.

  Instead of the cooling water supply device 33, various well-known cooling water supply means such as a form for recirculating the cooling water C and a form for discharging the supplied cooling water C (for example, tap water) are used. Is possible.

The polishing unit 40 includes, for example, two polishing unit main bodies 41, a unit main body connecting member 44, a unit main body rotating member 45, and a rotating shaft 46.
The polishing unit main body 41 includes a substrate holding surface plate 42, a substrate holding surface plate pressing portion 43, and a substrate holding surface plate driving motor (not shown).

The substrate holding surface plate 42 is capable of polishing the wafer W by adsorbing and holding the wafer (substrate) W and sliding the wafer W on the polishing pad P, for example.
Further, the substrate holding surface plate 42 is connected to a substrate holding surface plate driving motor (not shown), and the substrate holding surface plate driving motor, for example, around the rotation axis O1 in the direction of the arrow R1 in the same direction as the arrow R2. It is designed to be rotated.

  As a result, the wafer W is slidably contacted with the polishing pad P rotating in the direction of the arrow R2 while being rotated in the direction of the arrow R1, so that the wafer is located closer to the rotation axis O2 of the surface plate body 32 than the rotation axis O1 of the substrate holding surface plate 42. Since the rotation of W and the rotation of the polishing pad P are opposite to each other, the relative speed between the wafer W and the polishing pad P increases, and the wafer W is positioned more on the outer peripheral side of the surface plate body 32 than the rotation axis O1 of the substrate holding surface plate 42. And the rotation of the polishing pad P are offset, and the relative speed between the wafer W and the polishing pad P decreases.

  The substrate holding surface plate pressing unit 43 moves, for example, the substrate holding surface plate 42 in the vertical direction indicated by the arrow TZ so that the substrate holding surface plate 42 contacts and separates from the polishing pad P and is pressed with a predetermined pressure. It is supposed to be.

  The unit main body connecting member 44 has two polishing unit main bodies 41 installed on the upper part thereof, and the two polishing unit main bodies 41 are reciprocated in the direction of the arrow TX by a TX direction driving unit (not shown). .

  As a result, the wafer W is moved relative to the polishing pad P and the arrow TX while rotating in the direction of the arrow R1, and is polished by being pressed against the polishing pad P.

  The unit main body connecting member 44 is connected to the rotary shaft 46 via the unit main body rotating member 45, and is moved up and down in the direction of the arrow TZ by a vertical drive unit (not shown). 46 allows rotation about the rotation axis O3.

  As a result, for example, when exchanging the wafer W, as shown by a two-dot chain line in FIG. 4, the unit main body connecting member 44 and the two polishing unit main bodies 41 are moved to the outside of the polishing pad holding surface plate 30. Can be done.

According to the substrate polishing apparatus 200 and the polishing pad holding method according to the second embodiment, the surface plate body 32 is formed of porous ceramics, and the frame body 32A is provided so as to surround the outer periphery of the porous ceramics. Since the main body 32 is decompressed by the decompression pump 34 and the polishing pad P is sucked and held on the polishing pad holding surface 32P of the surface plate main body 32, the polishing pad P can be held easily and stably. Further, air bubbles can be reliably removed from between the polishing pad P and the surface plate body 32.
As a result, it is possible to stably secure the polishing quality of the wafer W and improve the productivity when polishing the wafer W.

  Further, according to the substrate polishing apparatus 200 and the polishing pad holding method according to the second embodiment, the surface plate main body 32 is formed of porous ceramics, and the polishing pad P is sucked uniformly over the entire surface. Since it is held by suction, the polishing pad P can be held easily and stably.

In addition, according to the substrate polishing apparatus 200 and the polishing pad holding method according to the second embodiment, since the surface plate body 32 is formed of porous ceramics, the surface plate body 32 of the surface plate body 32 caused by pressure or the like when polishing is used. The deformation is suppressed and the wafer W can be stably polished.
Further, the surface plate main body 32 is prevented from being altered, worn, or deteriorated due to secular change, and stable polishing quality can be ensured over a long period of time.

  In addition, according to the substrate polishing apparatus 200 and the polishing pad holding method according to the second embodiment, the surface plate body 32 is sucked through the reduced pressure air flow path (reduced fluid flow path) 312U formed in the surface plate pressure reducing member 312. Therefore, the pressure can be uniformly reduced over a wide range of the surface plate body 32 with a simple configuration.

<Third Embodiment>
Next, a schematic configuration of a substrate polishing apparatus according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a partial longitudinal sectional view illustrating a schematic configuration of a substrate polishing apparatus according to a third embodiment of the present invention, and FIG. 8 is a diagram illustrating a schematic configuration of a surface plate support.
7 and 8, reference numeral 300 denotes a substrate polishing apparatus, and reference numeral 50 denotes a polishing pad holding surface plate. Others are the same as those of the second embodiment, and thus the same reference numerals are given and the description thereof is omitted.

The substrate polishing apparatus 300 includes, for example, a polishing pad holding surface plate 50 and a polishing unit 40 as shown in FIG.
While the wafer (substrate) W and the polishing pad holding surface plate 50 are moved relative to each other by the polishing unit 40, the wafer W can be polished by pressing and slidingly contacting the polishing pad P.

As shown in FIG. 7, the polishing pad holding surface plate 50 includes, for example, a surface plate support (surface plate cooling member, surface plate decompression member) 51, a surface plate body 32, and a cooling water supply device (pressure reduction means) 53. And a drive motor 35.
The surface plate main body 32 holds the polishing pad P on the polishing pad holding surface 32P and can be rotated around the rotation axis O2 in the direction of the arrow R2 by the drive motor 35.

  Further, the surface plate support 51 and the cooling water supply device (decompression unit) 53 are connected by, for example, a rotary joint (not shown) or the like, and sucking and circulating the cooling water C while rotating the surface plate support 51. It is possible to let

  In this embodiment, the cooling water supply device 53 includes a cooling water pump (decompression unit) 53P and a cooling device 53S, and the cooling water pump 53P includes a surface plate support (a surface plate cooling member, a surface plate decompression unit). The cooling water C is sucked from the member 51 and sent to the cooling device 53S.

  The cooling device 53S depressurizes the cooling water C sent from the cooling water pump (decompression means) 53P and supplies it to the surface plate support 51 by the suction force of the cooling water pump 53P. As the cooling water pump 53P, various pumps that transfer water with a negative pressure can be applied.

  Hereinafter, the surface plate support member 51 will be described with reference to FIG. FIG. 8 is a diagram illustrating a schematic configuration of the surface plate support member 51 according to the third embodiment, and is a cross-sectional view taken along line VV in FIG. 7.

  As shown in FIG. 8, the surface plate support base (surface surface cooling member, surface plate pressure reducing member) 51 is made of, for example, stainless steel formed in a disk shape, and is formed of a concave portion on the upper surface. A water flow path (cooling medium flow path, fluid decompression flow path) 51U is formed two-dimensionally, and the cooling water flow path 51U is connected to the lower surface of the surface plate body 32 to support the surface plate body 32.

In this embodiment, the cooling water flow path (cooling medium flow path, fluid decompression flow path) 51U is configured by, for example, six blocks formed at intervals of 60 ° about the rotation axis O2.
Further, as shown in FIG. 8, each block constituting the cooling water channel 51U includes a plurality of circumferential recesses extending in the circumferential direction of the surface plate support member 51, and these circumferential recesses from the outer peripheral side to the inner periphery. A plurality of radial recesses alternately connected in the radial direction at one end side and the other end side in the circumferential direction toward the side.

  The cooling water inlet 51A is connected to the cooling water supply device 53 via the cooling water supply path 53A, and the cooling water C supplied to the cooling water flow path 51U via the cooling water supply path 53A is the surface plate support member 51. It is designed to circulate two-dimensionally on the top surface.

  The cooling water outlet 51B is connected to the cooling water supply device 53 via the cooling water recirculation path 53B, and the cooling water pump 53P sucks the cooling water C from the cooling water outlet 51B via the cooling water recirculation path 53B. Then, the refrigerant is refluxed to the cooling device 53S. Further, for example, the cooling water outlet 51B is formed to be smaller than the cooling water supply path 53A, and is configured so that the cooling water efficiently has a negative pressure.

  Since the cooling water reduced to a negative pressure with respect to the outside air flows through the cooling water flow path 51U, the cooling water in the surface plate main body 32 is reduced to a negative pressure and the suction force to the polishing pad holding surface 32P. And the temperature of the polishing pad P and the wafer W are suppressed during polishing so that the surface plate body 32 is cooled.

  As a result, the cooling water flowing in from the cooling water inlet 51A positioned on the outer peripheral side of the surface plate support member 51 smoothly flows in the circumferential direction and the radial direction toward the cooling water outlet 51B positioned on the inner peripheral side. Negative pressure is generated in the cooling water.

  Since the surface plate main body 32 and the polishing unit 40 are the same as those in the second embodiment, the same reference numerals are given and the description thereof is omitted.

According to the substrate polishing apparatus 300 according to the third embodiment, it is possible to obtain the same effect as in the second embodiment.
Further, according to the substrate polishing apparatus 300 and the polishing pad holding method according to the third embodiment, since the surface plate body 32 is formed of porous ceramics, it deteriorates due to rust or the like even if the cooling water C comes into contact. Therefore, the wafer W can be stably polished without deformation of the surface plate main body 32 due to pressure or the like due to polishing.

Further, according to the substrate polishing apparatus 300 and the polishing pad holding method according to the third embodiment, the negative pressure cooling water is circulated through the cooling water flow path 51U, whereby the surface plate body 32 is depressurized and distributed to the constant 51U. Since the surface plate main body 32 is depressurized by sucking out the cooling water C, the surface plate main body 32 can be efficiently depressurized and cooled with a simple configuration.
Moreover, since the structure is simple, the maintenance cost can be reduced while suppressing the initial investment cost.

<Fourth embodiment>
Next, a schematic configuration of a substrate polishing apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a conceptual diagram illustrating a schematic configuration of a substrate polishing apparatus according to the fourth embodiment of the present invention. In FIG. 9, reference numeral 400 denotes a substrate polishing apparatus.

As shown in FIG. 9, in the substrate polishing apparatus 400, for example, the polishing pad holding surface plate 30 is disposed so as to oppose the vertical direction. The wafer (substrate) W is disposed between the polishing pads P that are attracted to and held by the polishing pad holding surface 32P of the polishing pad holding surface plate 30 that is disposed opposite to the polishing pad holding surface plate 30 to polish the wafer W. .
In the fourth embodiment, instead of the polishing pad holding surface plate 30, a polishing pad holding surface plate 50 may be used, or the polishing pad holding surface plate 30 and the polishing pad holding surface plate 50 may be used in combination.

  In addition, in FIG. 9, illustration is abbreviate | omitted about the cooling water supply apparatus 33 which concerns on 2nd Embodiment, the pressure reduction pump 34, and the cooling water supply apparatus 53 which concerns on 3rd Embodiment. Further, the polishing pad holding surface plate 30 and the polishing pad holding surface plate 50 are the same as those in the second embodiment and the third embodiment, and thus the same reference numerals are given and the description thereof is omitted.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention.

For example, in the above embodiment, the surface plate bodies 12 and 32 are made of alumina having a thermal expansion coefficient (linear expansion coefficient) of 1 to 5 × 10 ⁻⁶ / K, a porosity of about 40%, and an average pore diameter of about 20 μm. The case of being formed of porous ceramics made of Al ₂ O ₃ ) ceramics has been described. In addition to alumina (Al ₂ O ₃ ) ceramics having properties other than those described above, zirconia, silicon carbide, silicon nitride, nitriding Other types of porous ceramics including aluminum can be arbitrarily set.

  The three-dimensional porous body is not limited to porous ceramics, and a three-dimensional porous body made of various metal materials such as stainless steel and other materials can be used.

  Moreover, in 2nd Embodiment and 3rd Embodiment, although the case where the surface plate main body 32 was provided with the frame 32A was demonstrated, whether it is provided with the frame 32A can be set arbitrarily.

  Moreover, in the said embodiment, although the polishing pad holding | maintenance surface plate 10 was fixed to 10 A of bases, the case where the surface plate support bases 31 and 51 were rotationally driven was demonstrated, whether the surface plate main body is rotationally driven. It can be set arbitrarily as required.

  In the above embodiment, the polishing pad holding surface plate 10 and the polishing pad holding surface plates 30 and 50 are disposed on the lower side, and the substrate polishing units 20 and 40 disposed above the polishing pad P hold the wafer W. The case where the wafer W is polished by moving relative to the polishing pad P while pressing the wafer W has been described. However, the polishing pad holding surface plate 10, the polishing pad holding surface plates 30, 50, and the substrate polishing units 20, 40 are described. It is possible to arbitrarily set which of these is arranged upward or along the horizontal direction (rotation axis is in the horizontal direction).

  Moreover, in the said 1st Embodiment, although the case where the surface plate main body 12 was decompressed from the lower surface through the air suction hole 11H for pressure reduction opened to the polishing pad holding surface 12P of the surface plate cooling member 11B was demonstrated, for example, It is good also as a structure which decompresses the surface plate main body 12 from the side surface of the surface plate main body 12, It is possible to set arbitrarily the path | route of the pressure reduction air flow path, etc. in the case of decompressing the surface plate main body 12 within a known technical range. is there.

  Moreover, in the said embodiment, although the case where the board | substrate was the wafer W was demonstrated, it is not limited to the wafer W, The board | substrate consisting of ceramics, such as a glass substrate and a sapphire, and the board | substrate of grinding | polishing object are set arbitrarily. Can do.

  Moreover, in the said embodiment, although the polishing pad holding | maintenance surface plate 10 and 30 was provided with the surface plate cooling members 11B and 312, the polishing pad holding | maintenance surface plate 10 and 30 was provided with the surface plate cooling members 11B and 31. Whether or not can be set arbitrarily.

  The form and shape of the cooling water flow path 11U in the surface plate cooling member 11B, the cooling water flow path 311U in the surface plate cooling member 311, the reduced pressure air flow path 312U in the surface plate pressure reducing member 312 and the cooling water flow path 51U in the surface plate support 51. The configuration such as the arrangement can be arbitrarily set.

  According to the polishing pad holding surface plate, the substrate polishing apparatus, and the polishing pad holding method according to the present invention, the polishing pad can be easily and stably held, and air bubbles are generated between the polishing pad and the surface plate body. Can be removed reliably, so that it can be used industrially.

O1 rotation axis O2 rotation axis W Wafer (substrate)
P Polishing pad 10, 30, 50 Polishing pad holding surface plate 11, 311 Surface plate cooling member 11U, 311U Cooling water flow path (cooling medium flow path)
11H Depressurizing air suction hole 12, 32 Surface plate main body 12P, 32P Polishing pad holding surface 13, 33, 53 Cooling water supply device 13P, 33P Cooling water pump 13S, 33S, 53S Cooling device 14, 34 Depressurization pump (decompression means)
14L, 34L Reduced pressure air suction line (reduced pressure line)
20, 40 Polishing units 21, 42 Substrate holding surface plate 51 Surface plate support (surface plate cooling member, surface plate decompression member)
51U Cooling water channel (cooling medium channel, fluid decompression channel)
53B Cooling water return path (decompression line)
53P Cooling water pump (pressure reduction means)
100, 200, 300 substrate polishing apparatus

Claims (8)

A polishing pad holding surface plate that is capable of holding a polishing pad, is pressed against the polishing pad, is relatively moved, and is used for polishing the substrate,
A platen body having a polishing pad holding surface formed of a three-dimensional porous body and capable of holding the polishing pad;
Decompression means;
With
A polishing pad holding surface plate, wherein the pressure reducing means depressurizes the surface plate body so that the polishing pad is sucked and held on a polishing pad holding surface. The polishing pad holding surface plate according to claim 1,
The three-dimensional porous body is
A polishing pad holding surface plate characterized by being a porous ceramic. The polishing pad holding surface plate according to claim 1 or 2,
A platen support that is disposed on a connection surface located on the opposite side of the polishing pad holding surface of the platen body and supports the platen body;
The decompression means includes
A polishing pad holding platen configured to depressurize the platen body through a vacuum fluid passage formed in the platen support. The polishing pad holding surface plate according to claim 3,
A cooling water supply means for cooling the platen body,
The surface plate support is
A decompression section formed with a decompression air flow path and connected to the decompression means;
A surface plate cooling member formed with a cooling water flow path and connected to the cooling water supply means,
The pressure reducing part and the surface plate cooling member are arranged in this order from the connection surface. The polishing pad holding surface plate according to claim 3,
A cooling water supply means for cooling the platen body,
The surface plate support is
A surface plate cooling member formed with a cooling water flow path and connected to the cooling water supply means,
The decompression means includes
A polishing pad holding surface plate comprising a cooling water pump provided in the cooling water supply means and depressurizing the inside of the surface plate body by sucking cooling water in the cooling water flow path. The polishing pad holding surface plate according to any one of claims 1 to 5,
A polishing unit comprising: a substrate holding surface plate that holds the substrate and is rotatable about an axis perpendicular to the surface to be polished of the substrate; and a substrate holding surface plate pressing portion that presses the substrate against the polishing pad. When,
A substrate polishing apparatus comprising: Two polishing pad holding surface plates according to any one of claims 1 to 5,
The polishing pad holding surface plate is
The substrate polishing is characterized in that the polishing pad holding surfaces are arranged to face each other so that the substrate can be pressed, and at least one of the polishing pads rotates so that the polishing pad and the substrate can move relative to each other. apparatus. A polishing plate holding method in a surface plate holding a polishing pad, and a substrate polishing apparatus capable of pressing and relative movement of a substrate against the polishing pad,
The surface plate is
A polishing pad holding surface formed of a three-dimensional porous body and capable of holding the polishing pad;
A polishing pad holding method, wherein the polishing pad is sucked and held on the holding surface by reducing the pressure of a three-dimensional porous body portion of the surface plate by a pressure reducing means.

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