JPH09225812A - Polishing method and device for semiconductor substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure an even polishing of a semiconductor substrate in the surface thereof by means of a polishing pad having elasticity. SOLUTION: An elastic polishing pad 2 is adhered to a surface of flat substrate retaining part of a surface plate 1. Above a first region from the central to the circumferential edge parts of the pad 2 a substrate retaining head 4 rotating while holding a semiconductor substrate 3, and the substrate 3 is pressure contacted while being rotated, to the first region. A polishing agent 5 is dropped onto the pad 2 by the specified amount. Above a second region from the center to the circumferential parts of the surface plate 1 pad pressuring means 7 for pressurizing the pad 2 are arranged. The means 7 is composed of a disc-shaped pad pressurizing plate 8A and a rotating shat 9 retaining the plate 8A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate polishing method and apparatus for performing chemical mechanical polishing (CMP) for flattening the surface of a semiconductor substrate made of, for example, silicon.

[0002]

2. Description of the Related Art Since 1990, in chemical mechanical polishing of a semiconductor substrate made of silicon or the like, the diameter of the semiconductor substrate is increased to 10 cm or more, and the polishing tends to be single-wafer processing. Further, since the rule of the pattern formed on the semiconductor substrate is extremely miniaturized to 0.5 μm or less,
Uniform polishing is required over the entire surface of a semiconductor substrate.

A semiconductor substrate polishing method and polishing apparatus according to a first conventional example will be described below with reference to the drawings.

FIG. 8 shows a schematic structure of a semiconductor substrate polishing apparatus of the first conventional example. In FIG. 8, reference numeral 21 denotes a rigid substrate holding portion 21a having a flat surface and the substrate holding portion 21a. Rotating shaft 21b extending vertically downward from the lower surface
And a rotating means (not shown) for rotating the rotating shaft 21b. An elastic polishing pad 22 is attached to the surface of the substrate holding portion 21a of the surface plate 21. A substrate holding head 24 that holds and rotates the semiconductor substrate 23 is provided above the polishing pad 22, and the semiconductor substrate 23 is pressed against the first region of the polishing pad 22 while being rotated by the substrate holding head 24. To be done. Further, 25 is a polishing agent, and the polishing agent 25 is dropped from the polishing agent supply pipe 26 on the polishing pad 22 by a predetermined amount.

In the semiconductor substrate polishing apparatus configured as described above, the substrate holding head 24 polishes the semiconductor substrate 23 while rotating the surface plate 21 to rotate the polishing pad 22 supplied with the polishing agent 25. When pressed against the pad 22, the surface of the semiconductor substrate 23 is polished under pressure and relative speed.

At this time, if there are irregularities on the surface of the semiconductor substrate 23, the convex portion of the semiconductor substrate 23 has a large contact pressure with the polishing pad 22, so that the polishing rate becomes fast, while the concave portion of the semiconductor substrate 23 has Since the contact pressure with the polishing pad 22 is small, the polishing rate becomes slow. Therefore, the irregularities on the surface of the semiconductor substrate 23 are alleviated and the surface of the semiconductor substrate 23 becomes flat. This polishing technique is described in, for example, "January 1994, Monthly Semiconduc
pages 58-59 and "Soli
d State Technology "July. 1
992 / Japanese version This is introduced on pages 32-37.

[0007]

However, the polishing apparatus and the polishing method for the semiconductor substrate of the first conventional example have the following problems described with reference to FIGS. 9 to 11.

FIG. 9 (a) qualitatively shows the relationship between the pressing time for the polishing pad 22 and the thickness of the polishing pad 22, the vertical axis being the thickness of the polishing pad, and the horizontal axis being the polishing pad. The pressurization time from the start of pressurization is shown. FIG.
(B) qualitatively shows the time course of the recovery of the polishing pad thickness when the pressure is set to 0 after being pressurized at a constant pressure, and the vertical axis is the thickness of the polishing pad, The horizontal axis indicates the time after the pressure is reduced to 0 after pressurization.

FIG. 10 is a schematic plan view of the polishing apparatus for explaining that the pressing time of the polishing pad 22 varies depending on the radial position of the polishing pad 22, and FIG. 11 shows
Diameter direction of surface plate 21 during polishing (VI in FIG. 10
FIG. 6 is a schematic cross-sectional view showing a cross-sectional structure along line (VI).

When an elastic material such as a non-woven fabric type or a urethane foam type, which is generally widely used, is used as the polishing pad 22, as shown in FIG. 9A, at the moment when the pressure starts to be applied (within several seconds), The amount of elastic deformation varies depending on the time from the start of pressurization, and as shown in FIG. 9 (b),
When the pressure is released, the amount of elastic deformation gradually recovers over time.

By the way, according to the polishing method of the first conventional example as shown in FIG.
3 (that is, the time when the polishing pad 22 receives pressure) is different. That is, the radius r shown in FIG.
Position a of 1, position b of radius r2, position c of radius r3
And, the time during which the polishing pad 22 is in contact with the semiconductor substrate 23 and receives pressure is different. Further, at the positions a, b, and c shown in FIG. 10, the non-pressurized time (time for elastic recovery) is different. Therefore, in the polishing pad 22 that is in contact with the semiconductor substrate 23, at the position b of the radius r2 that passes through substantially the center of the semiconductor substrate 23, the pressing time is relatively long and the recovery time is short. While the amount of elastic deformation is large, the amount of elastic deformation of the polishing pad 22 is relatively short at the position a having a radius r1 and the position c having a radius r3 that are in contact with the peripheral portion of the semiconductor substrate 23 because the pressing time is relatively short and the recovery time is long. Is small.

Therefore, as shown in FIG. 11, when viewed in a radial cross section, the thickness of the polishing pad 22 is thin in the vicinity of the center of the radius of the semiconductor substrate 23 (position b) and is small. The inner and outer portions (position a and position c) of the radius become thick.

In this state, when polishing is performed with the polishing pad 22 against the flat semiconductor substrate 23 under pressure, the semiconductor substrate 23 receives pressure from the polishing pad 22 at the inner and outer portions of the radius of the semiconductor substrate 23. Is high, the pressure applied to the semiconductor substrate 23 from the polishing pad 22 is low near the center of the radius of the semiconductor substrate 23. This in-plane pressure difference of the semiconductor substrate 23 appears as a difference in polishing rate, and the polishing rate near the center of the radius of the semiconductor substrate 23 is slower than the inside and outside portions of the radius of the semiconductor substrate 23. However, the semiconductor substrate 23 cannot be uniformly polished over the entire surface.

Therefore, as shown in FIG. 12 and described in “August 1993, Nikkei Microdevices” page 81, a method of using the deformation of the semiconductor substrate 33 against the elastic deformation of the polishing pad 32 has been proposed. ing.

The semiconductor substrate polishing method and polishing apparatus according to the second conventional example are as follows. That is, surface plate 3
A polishing pad 32 having elasticity is attached to the top of the sheet 1. Below the substrate holding head 34 that holds the semiconductor substrate 33, a hermetic seal formed by a head body 35 having a recess and an elastically deformable plate-like elastic body 36 provided in the recess of the head body 35. A space 37 is provided, and pressurized gas whose pressure is controlled is introduced into the sealed space 37 from a gas supply passage 38. In this way, the semiconductor substrate 33 is pressed against the polishing pad 32 through the elastic body 36 by the pressurized gas introduced into the sealed space 37, so that the semiconductor substrate 33 is uniformly pressed from the back surface and is evenly pressed. It is intended to be polished.

However, when the polishing pad 32 has a difference in thickness and elastic deformation amount, the semiconductor substrate 33 must be deformed (bent) to follow the unevenness of the surface of the polishing pad 32. Therefore, a pressure difference occurs due to the force (pressure) required to deform the semiconductor substrate 33,
After all, the problem that uniform pressing cannot be achieved and the semiconductor substrate 33 cannot be pressed uniformly has not been solved.

In view of the above, it is an object of the present invention to enable a semiconductor substrate to be uniformly polished in the plane of the semiconductor substrate with an elastic polishing pad.

[0018]

In order to achieve the above-mentioned object, a solution means provided by the invention of claim 1 is a polishing apparatus for a semiconductor substrate, which comprises a platen having a flat surface for planar movement, and the plate. An elastic polishing pad placed on the flat surface of the board, and a semiconductor substrate holding the semiconductor substrate to be polished and pressing the semiconductor substrate while rotating the semiconductor substrate to the circular first region of the polishing pad. Means, an abrasive supply means for supplying an abrasive onto the polishing pad, and a pad pressurizing means having a pad pressurizing portion for pressing the second region of the polishing pad to elastically deform the polishing pad. Is provided.

According to the structure of claim 1, the pad pressing portion presses the polishing pad and elastically moves the polishing pad even during polishing, that is, other than the time when the semiconductor substrate is pressing the first region of the polishing pad. It can be transformed. Since the polishing pad elastically deformed by the pad pressing unit recovers gently, it does not completely recover when it reaches the semiconductor substrate. Therefore, the deformation of the polishing pad when it is pressed by the semiconductor substrate during polishing. The quantity is small. The first region of the polishing pad has a circular shape, and the region of the polishing pad that contacts the peripheral portion of the semiconductor substrate is larger than the region of the polishing pad that contacts the central portion of the semiconductor substrate.
Even if the pressure applied by the semiconductor substrate is short, the amount of deformation of the polishing pad due to the pressure applied by the semiconductor substrate is small, so that the difference in thickness generated in the polishing pad can be reduced.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a configuration in which the plane motion is a rotary motion is added.

According to a third aspect of the present invention, in addition to the configuration of the first aspect, the pad pressing portion has a smooth pressing surface.

According to a fourth aspect of the present invention, in addition to the configuration of the first aspect, the pad pressing portion is made of resin.

According to a fifth aspect of the present invention, in addition to the configuration of the first aspect, the pad pressing portion has a circular pressing surface.

According to a sixth aspect of the invention, in addition to the structure of the first aspect, a structure in which the pad pressing portion has an annular pressing surface is added.

According to the structure of claim 6, since the pressing surface of the pad pressing portion is annular, the area of the polishing pad that contacts the peripheral portion of the semiconductor substrate is more than the area of the polishing pad that contacts the central portion of the semiconductor substrate. Since more pressure is applied to the polishing pad, the sum of the amount of pressure applied by the pad pressing unit and the amount of pressure applied by the semiconductor substrate to the polishing pad is substantially the same in each region of the polishing pad.

According to a seventh aspect of the present invention, in the structure according to the fifth or sixth aspect, the plane movement is a rotational movement, and the center of the pressing surface of the pad pressing portion and the center of the first area are the constant. A configuration is added which is located on a concentric circle centered on the center of rotation of the rotary motion of the board.

According to the structure of claim 7, the area where the polishing pad is pressed by the semiconductor substrate is surely pressed by the pad pressing portion and is in the process of recovering from the elastic deformation. More maintained.

According to an eighth aspect of the invention, in addition to the configuration of the seventh aspect, the diameter of the pressing surface of the pad pressing portion is larger than the diameter of the first region.

According to a ninth aspect of the present invention, in the structure according to the first aspect, the pad pressing portion has a trapezoidal pressing surface that expands outward from the center of rotation of the rotary motion of the surface plate. It is something to add.

According to the structure of claim 9, since there is no significant difference in the time of pressing by the pad pressing portion between the inner portion and the outer portion of the region of the polishing pad pressed by the pad pressing portion, the polishing is performed. The amount of deformation in which the pad is elastically deformed by the pad pressing portion is substantially uniform.

The invention of claim 10 is based on the structure of claim 1.
The second region has a configuration in which it is almost the entire region of the polishing surface of the polishing pad except the first region.

According to the structure of claim 10, the polishing pad comprises:
Since the entire surface is constantly pressed by the semiconductor substrate and the pad pressing portion, the entire surface of the polishing pad always holds a certain amount of elastic deformation.

The invention of claim 11 is based on the structure of claim 1.
A structure in which a concave groove for supplying the polishing agent to the polishing surface of the polishing pad is formed on the pressing surface of the pad pressing portion is added.

According to the eleventh aspect, the new polishing agent can be supplied also to the region of the polishing surface of the polishing pad which is in contact with the pressing surface of the pad pressing portion.

The invention of claim 12 is based on the structure of claim 1.
The pad pressing unit is composed of a roller having a rotation axis substantially parallel to the flat surface of the surface plate, and is pressed against the second region of the polishing pad to rotate with the movement of the surface plate. It is something to add.

According to the twelfth aspect, the polishing pad can be pressed by the pad pressing section in a state where the friction between the polishing pad and the pad pressing section is reduced.

According to a thirteenth aspect of the present invention, in the structure of the twelfth aspect, the plane motion is a rotary motion, and the roller is
A configuration is added in which the ratio of the radii of each part of the cross section of the roller is a truncated cone shape that is equal to the ratio of the distance from the center of rotation of the part of the polishing pad where each part of the cross section of the roller contacts. .

According to the thirteenth aspect, when the surface plate rotates, the roller can rotate at the same speed as the rotation speed of the surface plate, so that friction between the polishing pad and the roller can be eliminated. it can.

According to a fourteenth aspect of the present invention, in addition to the configuration of the twelfth aspect, the roller has a cylindrical configuration.

According to a fifteenth aspect of the present invention, a configuration in which the plane movement is a linear movement is added to the construction of the fourteenth aspect.

According to a sixteenth aspect of the invention, in addition to the constitutions of the thirteenth to fifteenth aspects, the roller is constituted by a plurality of coaxially arranged roller members.

According to a seventeenth aspect of the present invention, in addition to the configuration of the twelfth aspect, a configuration in which the second region is wider than the first region is added.

According to an eighteenth aspect of the present invention, in the structure according to the thirteenth to fifteenth aspects, the roller presses the vicinity of an area of the polishing pad where the time when the polishing pad and the semiconductor substrate are in contact with each other is relatively small. Is added.

According to the eighteenth aspect, it is possible to reduce the difference in the pressing time of the polishing pad in the first region.

According to a nineteenth aspect of the present invention, there is provided a method of polishing a semiconductor substrate, wherein a semiconductor substrate is polished on an elastic polishing pad placed on the flat surface of a surface plate having a flat surface that moves in a plane. A polishing agent supplying step of supplying a polishing agent, a substrate polishing step of polishing the semiconductor substrate while pressing the semiconductor substrate to the circular first area of the polishing pad, and a second area of the polishing pad. Then, a pad pressing step for elastically deforming the second region is provided.

According to the structure of claim 19, similarly to the structure of claim 1, the pad pressing portion can press the polishing pad to elastically deform the polishing pad, and the pad pressing portion elastically deforms. Since the polishing pad recovers gently, the amount of deformation of the polishing pad when pressed by the semiconductor substrate during polishing is small.

According to a twentieth aspect of the present invention, in the structure according to the nineteenth aspect, in the pad pressing step, the second polishing pad
The pressing force for pressing the area is equal to or more than the pressing force for pressing the first area of the polishing pad in the substrate polishing step.

According to the twentieth aspect, the entire region of the polishing pad, particularly the region contacting the peripheral portion of the semiconductor substrate is sufficiently pressurized, so that the entire region of the polishing pad contacting the semiconductor substrate is elastically deformed substantially uniformly. It becomes a state.

According to a twenty-first aspect of the invention, a configuration in which the plane motion is a rotary motion is added to the configuration of the nineteenth aspect.

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a semiconductor substrate polishing apparatus and a polishing method according to each embodiment of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a schematic configuration diagram illustrating a polishing apparatus for a semiconductor substrate according to a first embodiment of the present invention. In FIG. 1, 1 is a rigid body having a flat surface. A platen having a substrate holding part 1a made of, a rotating shaft 1b extending vertically downward from a lower surface of the substrate holding part 1a, and a rotating means (not shown) for rotating the rotating shaft 1b,
A polishing pad 2 having elasticity is attached to the surface of the substrate holding portion 1a of the surface plate 1. A substrate holding head 4 that holds and rotates the semiconductor substrate 3 is provided above the circular first region that extends from the central portion to the peripheral portion of the surface plate 1. The substrate holding head 4 allows the semiconductor substrate to be rotated. While rotating, 3 is pressed against the first region of the polishing pad 2 on the surface plate 1. The polishing agent 5 is dropped onto the polishing pad 2 by a predetermined amount from the polishing agent supply pipe 6 and is supplied between the polishing pad 2 and the semiconductor substrate 3.

As a feature of the first embodiment, above the second region extending from the central portion to the peripheral portion of the surface plate 1,
Pad pressing means 7 for pressing the second region of the polishing pad 2
The pad pressing means 7 is composed of a disk-shaped pad pressing plate 8A as a pad pressing portion and a rotary shaft 9 for holding the pad pressing plate 8A.

The operation of the polishing apparatus according to the first embodiment will be described below.

First, the abrasive 5 containing abrasive particles is quantitatively dropped onto the rotating polishing pad 2 by the abrasive supply pipe 6.
By doing so, the polishing agent 5 is diffused by the rotation of the surface plate 1 and spreads over the entire surface of the polishing pad 2.

Next, the substrate holding head 4 supporting the semiconductor substrate 3 and the pad pressing means 7 are rotated and lowered to bring the semiconductor substrate 3 and the pad pressing plate 8A into pressure contact with the polishing pad 2, respectively.

By doing so, the first region of the polishing pad 2 having elasticity is pressed by the pad pressing plate 8A and elastically deformed to be recessed by a predetermined amount. Since the surface plate 1 is rotating, the first region of the polishing pad 2, which is recessed by a predetermined amount, reaches the semiconductor substrate 3 while recovering at the next moment.

Since the non-woven fabric type urethane foam type polishing pad 2 generally used for polishing has a very slow recovery rate as compared with the elastic deformation rate when pressurized,
If the surface plate 1 is rotated at a certain high speed (for example, 30 rpm or more), the pad pressure plate 8A in the polishing pad 2
Since the elastic deformation of the polishing pad 2 has not recovered much even when the region compressed by means of reaching the semiconductor substrate 3, the amount of deformation is almost the same when the semiconductor substrate 3 is contacted and pressed by the semiconductor substrate 3. The second region of the polishing pad 2, which is compressed by the pad pressing plate 8A, comes into sliding contact with the semiconductor substrate 3 in a deformed state.

When the polishing pad 2 elastically deformed by the pad pressing plate 8A reaches the semiconductor substrate 3, the polishing pad 2
Deformation amount of the pressure during polishing (= pressure from the semiconductor substrate 3)
By making the amount of deformation substantially equal to the amount of deformation by the above, the amount of deformation of the polishing pad 2 hardly changes even when pressure is applied from the semiconductor substrate 3.

FIG. 2A shows the planar shape of the pad pressing plate 8A and the position with respect to the polishing pad 2 in the first embodiment. The center of the disk-shaped pad pressing plate 8A is on the circle having the same radius as the center of the semiconductor substrate 3 and the polishing pad 2, and the diameter of the pad pressing plate 8A is sufficiently larger than the diameter of the semiconductor substrate 3.

When the polishing pad 2 is pressed using the pad pressing plate 8A according to the first embodiment, at the time when the polishing pad 2 reaches the semiconductor substrate 3, the entire area of the polishing pad 2 in contact with the semiconductor substrate 3 is reached. Is in the process of recovery from elastic deformation, and the entire region of the polishing pad 2 in contact with the semiconductor substrate 3 is elastically deformed.
The uniform polishing can be performed.

In this case, when the polishing pad 2 is pressed by a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3 using the pad pressing plate 8A according to the first embodiment, the semiconductor substrate 3 in the polishing pad 2 is pressed. The region in contact with the peripheral portion is also sufficiently pressed, and the semiconductor substrate 3 in the polishing pad 2 is
The entire area in contact with will be elastically deformed almost uniformly,
Since the region of the polishing pad 2 that is in contact with the peripheral portion of the semiconductor substrate 3 is also sufficiently pressurized, the entire region of the polishing pad 2 that is in contact with the semiconductor substrate 3 is elastically deformed substantially uniformly, and the semiconductor substrate of the polishing pad 2 is in a deformed state. The surface in contact with 3 becomes flat. Therefore, since the polishing pad 2 polishes the semiconductor substrate 3 with a uniform pressure, the semiconductor substrate 3 can be polished with good uniformity.

Further, in the first embodiment, the pad pressure plate 8A may be rotated or may not be rotated. When the pad pressing plate 8A is rotated, it may be rotated in the same direction as the surface plate 1 (polishing pad 2) as shown in FIG. 1, or as shown in FIG. It may be rotated in the opposite direction to the (polishing pad 2). When the pad pressure plate 8A is rotated in the direction opposite to the surface plate 1, the polishing pad 2
The polishing agent 5 supplied onto the outer surface of the polishing pad 2 is directed toward the outside of the polishing pad 2 due to the centrifugal force associated with the rotation of the polishing pad 2, but after hitting the pad pressing plate 8A on the way to the outside, the pad pressing plate 8A is rotated. Along with this, it is returned to the center side of the polishing pad 2 and used again for polishing the semiconductor substrate 2. Therefore, the amount of the polishing agent 5 used can be reduced.

(Second Embodiment) FIG. 2B shows the shape of the pad pressing plate 8B of the polishing apparatus according to the second embodiment. In the second embodiment, the pad pressure plate 8
B is an annular shape, and the center of the pad pressing plate 8B is on the circle of the same radius as the center of the semiconductor substrate 3 and the polishing pad 2,
The inner diameter of the pad pressing plate 8B is slightly larger than the diameter of the semiconductor substrate 3.

As described above, when the pad pressing plate 8B according to the second embodiment is used to press the polishing pad 2 with a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3,
Since the region of the polishing pad 2 that contacts the peripheral portion of the semiconductor substrate 3 is pressed more than the region that contacts the central portion of the semiconductor substrate 3, the amount of pressure applied to the polishing pad 2 by the pad pressing plate 8B and the semiconductor substrate 3 depend. The sum of the amount of pressurization is almost the same in each region of the polishing pad 2, and the entire region of the polishing pad 2 in contact with the semiconductor substrate 3 is elastically deformed substantially uniformly. Polishing can be performed.

Also in the second embodiment, the pad pressure plate 8B may or may not be rotated. When the pad pressure plate 8B is rotated, it may be rotated in the same direction as the surface plate 1 (polishing pad 2), or as shown in FIG. You may rotate in the direction. When the pad pressure plate 8B is rotated in the opposite direction to the surface plate 1, the polishing agent 5 supplied onto the polishing pad 2 is moved toward the outside of the polishing pad 2 as in the first embodiment. When it hits 8B, it is returned to the center side of the polishing pad 2 as the pad pressing plate 8B rotates, and is used again for polishing the semiconductor substrate 3.

(Third Embodiment) FIG. 2C shows the shape of the pad pressing plate 8C of the polishing apparatus according to the third embodiment. In the third embodiment, as indicated by the solid line in FIG. 2C, the pad pressure plate 8C has a fan shape that is line-symmetric with respect to the center line indicated by the alternate long and short dash line. Is the same as the center of the polishing pad 2.

As described above, when the pad pressing plate 8C according to the third embodiment is used to press the polishing pad 2 with a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3,
Since the area of each arc passing through each point in the radial direction of the polishing pad 2 is equalized by the pad pressing plate 8C, the pad pressing plate in each area of each arc passing each point in the radial direction of the polishing pad 2 becomes equal. The amount of deformation by 8C becomes equal. Therefore, the amount of deformation of the polishing pad 2 when reaching the semiconductor substrate 3 can be made substantially equal to the amount of deformation by the semiconductor substrate 3, so that the deformation of the polishing pad 2 does not occur during polishing, and the amount of deformation relative to the semiconductor substrate 3 is increased. Uniform polishing can be performed.

The shape of the pad pressure plate 8C is shown in FIG.
As indicated by the solid line in (c), the line may be symmetrical with respect to the center line indicated by the alternate long and short dash line, but the side of the two fan-shaped sides on which the abrasive 5 strikes as the polishing pad 2 rotates. As shown by the broken line in FIG. 2C, the side may have a shape in which the outer side is located on the rear side in the rotation direction of the polishing pad 2 with respect to the inner side with respect to the radial direction of the fan shape. By doing so, the polishing agent 5 supplied onto the polishing pad 2 moves toward the outside of the polishing pad 2 due to the centrifugal force caused by the rotation of the polishing pad 2, but on the way to the outside, the side edge of the pad pressing plate 8C is moved. After hitting, the wafer is returned to the center side of the polishing pad 2 and the semiconductor substrate 2
It is used again for polishing.

(Fourth Embodiment) FIG. 2D shows the shape of the pad pressing plate 8D of the polishing apparatus according to the fourth embodiment. In the fourth embodiment, the pad pressure plate 8
D is a shape obtained by cutting out the circular shape of the semiconductor substrate 3 from the fan shape of the third embodiment.

As described above, when the polishing pad 2 is pressed with a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3 using the pad pressure plate 8D according to the fourth embodiment,
Since the sum of the amount of pressure applied by the pad pressure plate 8D and the amount of pressure applied by the semiconductor substrate 3 received by each arcuate region passing through each point in the radial direction of the polishing pad 2 is equal to the semiconductor substrate 3 of the polishing pad 2. Since the entire region is elastically deformed substantially uniformly, the semiconductor substrate 3 can be polished more uniformly.

The shape of the pad pressure plate 8D is shown in FIG.
As shown by the solid line in (d), the line may be symmetrical with respect to the center line indicated by the alternate long and short dash line, but the side of the two fan-shaped sides on which the polishing agent 5 strikes as the polishing pad 2 rotates. As shown by the broken line in FIG. 2D, the side may have a shape in which the outer side is located on the rear side in the rotation direction of the polishing pad 2 with respect to the inner side with respect to the radial direction of the fan shape. By doing so, the polishing agent 5 supplied onto the polishing pad 2 is directed to the outside of the polishing pad 2 by the centrifugal force caused by the rotation of the polishing pad 2, but on the way to the outside, the side of the pad pressing plate 8D is moved. After hitting, the wafer is returned to the center side of the polishing pad 2 and the semiconductor substrate 2
It is used again for polishing.

(Fifth Embodiment) FIG. 2E shows the shape of the pad pressing plate 8E of the polishing apparatus according to the fifth embodiment. In the fifth embodiment, the pad pressure plate 8
E is a shape obtained by cutting a circle having a diameter slightly smaller than that of the polishing pad 2 to a circle having a diameter slightly larger than that of the semiconductor substrate 3.

As described above, when the polishing pad 2 is pressed by a pressure equivalent to the polishing pressure applied by the semiconductor substrate 3 using the pad pressing plate 8E according to the fifth embodiment, the polishing pad 2
Since the polishing pad 2 is pressed by the polishing pressure over the entire surface, and the entire surface of the polishing pad 2 always maintains a constant deformation, the semiconductor substrate 3 can be polished more uniformly. it can.

(Sixth Embodiment) FIG. 3 shows a sixth embodiment of the present invention.
3 shows a sectional structure of the pad pressing means 7 of the polishing apparatus according to the embodiment.

As shown in FIG. 3, a circular plate-shaped body 10 is attached to the lower end of the rotary shaft 9, and the plate-shaped body 10 and the pad pressing plate 8 can be easily deformed in the vertical direction. They are connected by 11. A liquid or gas is filled in the sealed space 12 formed by the plate-shaped body 10, the flexible member 11 and the pad pressing plate 8.

By doing so, even if the area of the pad pressing plate 8 is large, the pad pressing plate 8 will not be affected by the polishing pad 2.
Can be uniformly pressed, so that the semiconductor substrate 3 can be uniformly polished.

As a feature of the sixth embodiment, a large number of concave grooves 13 are provided on the lower surface of the pad pressing plate 8. By doing so, even when the contact area between the pad pressing plate 8 and the polishing pad 2 is large as in the fifth embodiment, the polishing agent 5 is supplied to the surface of the polishing pad 2 through the concave groove 13. As a result, the polishing agent 2 is always supplied to the surface of the polishing pad 2, so that the polishing agent 5 is always present on the polishing pad 2. As a result, the polishing agent 5 that has deteriorated due to the polishing of the semiconductor substrate 3 can be renewed, and stable polishing can be achieved even if the pad pressing plate 8 is provided on the polishing pad 2.

In each of the above-mentioned embodiments, the surface of the pad pressing plate which contacts the polishing pad 2 is formed flat, and the pad pressing plate does not roughen the surface of the polishing pad 2.

The material of the pad pressing plate is not particularly limited, but if the pad pressing plate is made of resin, the pad pressing plate is not attacked by the abrasive, so that stable operation can be performed.

Further, in each of the above-described embodiments, the surface pressure of the pad pressing plate has been described as being equal to or higher than the pressure when polishing the semiconductor substrate 3. Even if it is small, the effect of the present invention can be expected.

In each of the above-described embodiments, the case where the rotating surface plate 1 is used has been described, but the same effect is obtained when the surface plate 1 performs reciprocating linear motion, circular motion, and the like. .

(Seventh Embodiment) FIG. 4 is a schematic perspective view illustrating a semiconductor substrate polishing apparatus according to a seventh embodiment of the present invention. In FIG. 4, substantially the same as the first embodiment. In addition, 1 is a substrate holder 1 made of a rigid body having a flat surface.
a surface plate having a rotating shaft 1b extending vertically downward from the lower surface of the substrate holding portion 1a and a rotating means (not shown) for rotating the rotating shaft 1b, the surface of the substrate holding portion 1a of the surface plate 1 Is attached with a polishing pad 2 having elasticity. A substrate holding head 4 that holds and rotates the semiconductor substrate 3 is provided above the circular first region that extends from the central portion to the peripheral portion of the surface plate 1. The substrate holding head 4 allows the semiconductor substrate to be rotated. While rotating, 3 is pressed against the first region of the polishing pad 2 on the surface plate 1. Abrasive 5
A predetermined amount is dropped from the polishing agent supply pipe 6 onto the polishing pad 2 and is supplied between the polishing pad 2 and the semiconductor substrate 3.

As a feature of the seventh embodiment, above the second region extending from the central portion to the peripheral portion of the surface plate 1,
Pad pressing means 1 for pressing the second region of the polishing pad 2
4 is provided, and the pad pressing means 14 is a truncated cone pad pressing roller 15A as a pad pressing portion.
And a rotary shaft 16 for holding the pad pressure roller 15A
Consists of

Further, the ratio of the radii of the pad pressing roller 15A at each part of the cross section is equal to the ratio of the distance from the center of rotation of the part of the polishing pad 2 where the part of the pad pressing roller 15A cross section is in contact. .

The operation of the polishing apparatus according to the seventh embodiment will be described below.

First, the abrasive 5 containing abrasive particles is quantitatively dropped onto the rotating polishing pad 2 by the abrasive supply pipe 6.
By doing so, the polishing agent 5 is diffused by the rotation of the surface plate 1 and spreads over the entire surface of the polishing pad 2.

Next, the substrate holding head 4 supporting the semiconductor substrate 3 and the pad pressing means 14 are rotated and lowered to make the semiconductor substrate 3 and the pad pressing roller 1
5A is pressed against the polishing pad 2, respectively.

FIGS. 7A and 7B are schematic cross-sectional views for explaining how the pad pressure roller 15A presses the polishing pad 2 to elastically deform it.

As shown in FIG. 7A, in the polishing pad 2, the recess 2a is formed because the region in contact with the central portion of the semiconductor substrate 3 is elastically deformed more. When the polishing pad 2 is pressed by the pad pressure roller 15A in this state, the convex portion 2b of the polishing pad 2 is moved to the pad pressure roller 1
Since it is strongly compressed by 5A, the first region of the polishing pad 2 is pressed by the pad pressure roller 15A and elastically deformed to be flattened by a predetermined amount as shown in FIG. 7B.

Since the surface plate 1 is rotating, the polishing pad 2
The first region, which is recessed and flattened by a predetermined amount, reaches the semiconductor substrate 3 while recovering at the next moment.

Since the non-woven fabric type urethane foam type polishing pad 2 generally used for polishing has a very slow recovery rate as compared with the elastic deformation rate when pressurized,
If the surface plate 1 is rotated at a high speed (for example, 30 rpm or more) to some extent, the elastic deformation of the polishing pad 2 is not sufficient even when the region of the polishing pad 2 compressed by the pad pressure roller 15A reaches the semiconductor substrate 3. Since it has not been recovered, even if the semiconductor substrate 3 is contacted and pressed by the semiconductor substrate 3, the amount of deformation is hardly changed, and the second pad compressed by the pad pressure roller 15A in the polishing pad 2 is used.
The region of (1) is in sliding contact with the semiconductor substrate 3 in a deformed state.

When the polishing pad 2 elastically deformed by the pad pressure roller 15A reaches the semiconductor substrate 3, the deformation amount of the polishing pad 2 is almost equal to the deformation amount due to the pressure during polishing (= pressure from the semiconductor substrate 3). By making them equal, the polishing pad 2 hardly deforms even when pressure is applied from the semiconductor substrate 3.

FIG. 5A shows the position of the pad pressure roller 15A in the seventh embodiment with respect to the polishing pad 2. Polishing pad 2 of pad pressure roller 15A
The length of the region in contact with is sufficiently larger than the diameter of the semiconductor substrate 3.

When the polishing pad 2 is pressed by using the pad pressure roller 15A according to the seventh embodiment, when the polishing pad 2 reaches the semiconductor substrate 3, all the polishing pad 2 is in contact with the semiconductor substrate 3. Since the region is in the process of recovering from the elastic deformation and the entire region of the polishing pad 2 in contact with the semiconductor substrate 3 is elastically deformed, the semiconductor substrate 3 can be uniformly polished.

In this case, when the polishing pad 2 is pressed with a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3 using the pad pressure roller 15A according to the seventh embodiment, the semiconductor substrate 3 in the polishing pad 2 is pressed. The region of the polishing pad 2 in contact with the semiconductor substrate 3 is elastically deformed substantially uniformly, and the region of the polishing pad 2 in contact with the peripheral region of the semiconductor substrate 3 is also sufficiently pressurized. Since the entire area of the polishing pad 2 in contact with the semiconductor substrate 3 is elastically deformed substantially uniformly, the first area of the polishing pad 2 in contact with the semiconductor substrate 3 becomes flat. Therefore, since the polishing pad 2 polishes the semiconductor substrate 3 with a uniform pressure,
The semiconductor substrate 3 can be polished with good uniformity.

Furthermore, when the surface plate 1 makes a rotary motion,
The pad pressure roller 15A is a truncated cone, and the ratio of the radii of each section of the cross section is the polishing pad 2 with which each section contacts.
By making it equal to the ratio of the distance from the center of rotation of the pad pressure roller 15A, the pad pressure roller 15A can obtain rotation that matches the rotation speed of the surface plate 1 on the contact surface of the pad pressure roller 15A with the polishing pad 2. Therefore, friction does not occur on the contact surface between the pad pressure roller 15A and the polishing pad 2. Therefore, by using the pad pressure roller 15A, since frictional heat is not generated and the pad pressure roller 15A is not polished, it is possible to avoid the temperature rise of the abrasive and the deformation of the pad pressure roller 15A. Stable polishing can be realized.

(Eighth Embodiment) FIG. 5B is a schematic perspective view showing the shape of the pad pressure roller 15B of the polishing apparatus according to the eighth embodiment. In the eighth embodiment, the pad pressure roller 15B is composed of a plurality of frustoconical roller members, and the radius ratio of each roller member is determined by the rotation of the portion of the polishing pad 2 in contact with each roller member. Equal to the ratio of the distance from the center.

When the polishing pad 2 is pressed with a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3 by using the pad pressure roller 15B according to the eighth embodiment, the polishing pad 2 comes into contact with the semiconductor substrate 3 in the polishing pad 2. Since the first region is elastically deformed substantially uniformly, the semiconductor substrate 3 can be polished more uniformly.

Even if the radius of each roller member is slightly different from the radius from the center of rotation of the portion of the polishing pad 2 in contact with each roller member, each roller member rotates independently, so that each roller member rotates independently. Since the rotation suitable for each position in sliding contact with the polishing pad 2 is possible, the friction can be further reduced as compared with the seventh embodiment, and more stable polishing can be realized.

(Ninth Embodiment) FIG. 5C is a schematic perspective view showing the shape of the pad pressure roller 15C of the polishing apparatus according to the ninth embodiment. In the ninth embodiment, the pad pressure roller 15C is composed of a plurality of, for example, four truncated cone-shaped roller members, and the ratio of the radii of the roller members depends on the portion of the polishing pad 2 in contact with the roller members. Equal to the ratio of the distance from the center of rotation. Further, for example, the four roller members are arranged at intervals of two, and are arranged at such positions as to press the vicinity of a region of the polishing pad 2 which is in contact with the vicinity of the peripheral portion of the semiconductor substrate 3.

When the polishing pad 2 is pressed with a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3 using the pad pressure roller 15C according to the ninth embodiment, the peripheral edge of the semiconductor substrate 3 in the polishing pad 2 is increased. Only the area in contact with the part is pressurized. The amount of deformation of the region of the polishing pad 2 in contact with the peripheral edge of the semiconductor substrate 3 when reaching the semiconductor substrate 3 is adjusted by adjusting the pressure of the pad pressure roller 15C, and the polishing pad 2 in contact with the vicinity of the central portion of the semiconductor substrate 3 is reached. By setting the deformation amount to be larger than the deformation amount of the region, the difference in polishing pressure caused by the deformation of the polishing pad 2 in the first region can be reduced, so that the semiconductor substrate 3 can be polished more uniformly. You can

In FIG. 5 (c), the pad pressure roller 15C has two roller members at both ends, but the number of roller members arranged at each end may be one or three. Or more. Further, although the space is provided between the outer roller member and the inner roller member, the space may not be provided.

(Tenth Embodiment) FIG. 6A shows the first embodiment.
0 pad pressure roller 15 of the polishing apparatus according to the embodiment
It is a schematic perspective view for showing the shape of D. In the tenth embodiment, the pad pressure plate roller 15D has a cylindrical shape, and the case where the surface plate 1 performs linear movement in one direction is shown.

When the polishing pad 2 is pressed at a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3 using the pad pressure plate roller 15D according to the tenth embodiment, the polishing pad 2 comes into contact with the semiconductor substrate 3 in the polishing pad 2. Since the first region is elastically deformed substantially uniformly, the semiconductor substrate 3 can be polished more uniformly.

By the way, when the surface plate 1 makes a rotary motion as in each of the above-described embodiments, the speed varies depending on the radius from the center of rotation of the surface plate 1, the speed is high at the outer peripheral portion and slow at the central portion. . Pad pressure roller 1 formed integrally
When 5D is used, since the pad pressure roller 15D rotates a certain amount, the relative speed at the contact surface between the polishing pad 2 and the pad pressure roller 15D is different due to the difference in the contact resistance with the polishing pad 2, so that the pad pressure roller 15D may slightly rotate. Friction will occur.

However, as shown in FIG.
When the surface plate 1 makes a linear motion, the relative speed becomes the same on the contact surface between the surface plate 1 and the pad pressure roller 15D. Therefore, by using the pad pressure roller 15D, frictional heat is not generated and Since the pad pressure roller 15D is not polished, it is possible to avoid the temperature rise of the polishing agent and the deformation of the pad pressure roller 15D.
Thereby, stable polishing can be realized. Further, the cylindrical pad pressure roller 15D has an advantage that it is easy to manufacture.

In this embodiment, the case where the linear motion of the surface plate 1 is in only one direction has been described.
The same effect can be obtained even when the reciprocating linear motion is performed. When the platen 1 makes a reciprocating linear motion, it is more preferable to provide the pad pressure rollers 15D at both ends of the first region of the polishing pad 2 in contact with the semiconductor substrate 3.

(Eleventh Embodiment) FIG. 6B shows the first embodiment.
Pad pressure roller 15 of the polishing apparatus according to the first embodiment
It is a schematic perspective view for showing the shape of E. In the eleventh embodiment, the pad pressure roller 15E is composed of a plurality of disc-shaped roller members arranged coaxially.

When the polishing pad 2 is pressurized with a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3 using the pad pressure plate roller 15E according to the eleventh embodiment,
Since the first region of the polishing pad 2 that is in contact with the semiconductor substrate 3 is elastically deformed substantially uniformly, the semiconductor substrate 3 can be polished more uniformly.

Further, even if the diameters of the roller members are slightly different, since each roller member rotates independently, rotation suitable for each roller member is possible. It can be further reduced, and thereby more stable polishing can be realized.

Furthermore, even when the surface plate 1 makes a rotary motion,
Since each roller member rotates independently, the polishing pad 2
Even if the distance from the center of rotation is different, the rotation speed of each roller member is almost the same as the speed of the portion of the polishing pad 2 in contact with each roller member, so friction is reduced compared to the tenth embodiment. Therefore, stable polishing can be obtained.

In this embodiment, the case where the surface plate 1 makes a linear motion in one direction has been described, but the same effect can be obtained even when the surface plate 1 makes a reciprocating linear motion. To be When the surface plate 1 makes a reciprocating linear motion,
It is more preferable to provide pad pressure rollers 15E at both ends of the first region of the polishing pad 2 in contact with the semiconductor substrate 3.

(Twelfth Embodiment) FIG. 6C shows the first embodiment.
Pad pressure roller 15 of the polishing apparatus according to the second embodiment
It is a schematic perspective view for showing the shape of F. In the twelfth embodiment, the pad pressure roller 15F is composed of a plurality of disk-shaped roller members arranged coaxially, and the plurality of roller members are located near the peripheral edge of the semiconductor substrate 3 in the polishing pad 2. It is installed at a position where the contact area is pressed. Specifically, the pad pressure roller 15
F is composed of four roller members, two on each end.

When the pad pressing roller 15F according to the twelfth embodiment is used to press the polishing pad 2 with a pressure equal to or higher than the polishing pressure applied by the semiconductor substrate 3,
Only the first region of the polishing pad 2 that contacts the peripheral portion of the semiconductor substrate 3 is pressed. Pad pressure roller 15F
By adjusting the pressure of the semiconductor substrate 3 in the polishing pad 2.
When the amount of deformation of the region in contact with the outer peripheral portion of the semiconductor substrate 3 when reaching the upper limit is made larger than the amount of deformation in the region of the polishing pad 2 in contact with the vicinity of the central portion of the semiconductor substrate 3, polishing during polishing is performed. Since the difference in the amount of deformation of the pad 2 can be reduced, the semiconductor substrate 3 can be polished more uniformly.

In addition, whether the surface plate 1 is rotating or linearly moving, each disk can rotate at the same speed as the polishing pad 2 contacting each disk. It is possible to achieve stable polishing without causing friction.

In FIG. 6 (c), the pad pressure roller 15F is shown to be composed of two roller members arranged at both ends. However, one pad pressure roller 15F or three or more roller members are provided at both ends. The same applies to the configuration in which the roller members are arranged. Further, although the gap is provided between the roller members at both ends, the gap may not be provided. Further, in the present embodiment, the case where the surface plate 1 makes a linear motion in one direction has been described, but the same effect can be obtained even when the surface plate 1 makes a reciprocating linear motion. When the surface plate 1 reciprocates linearly, it is more preferable to provide pad pressure rollers 15F at both ends of the first region of the polishing pad 2 in contact with the semiconductor substrate 3.

Further, each pad pressure roller 15 described above is used.
Since the surface of A to 15F in contact with the polishing pad 2 is flat, the surface of the polishing pad 2 is not roughened.

The pad pressure roller 15 described above is also used.
When A to 15F are formed of resin, stable operation can be performed without damaging the pad pressure rollers 15A to 15F with the polishing liquid.

Further, each pad pressure roller 15 described above is used.
Although the surface pressures of A to 15F have been described as being equal to or higher than the pressure during polishing of the semiconductor substrate 3, the effect of the present invention can be expected if it is 1/2 or more of the pressure during polishing.

[0120]

According to the semiconductor substrate polishing apparatus of the first aspect of the present invention, the polishing pad elastically deformed by the pad pressing portion recovers gently, so that it completely recovers even when it reaches the semiconductor substrate. The amount of elastic deformation of the polishing pad when pressed by the semiconductor substrate during polishing is small,
Since the difference in the thickness of the polishing pad is small, the flatness of the polishing pad is maintained. For this reason, the pressure that the semiconductor substrate receives from the polishing pad during polishing becomes substantially uniform over the entire surface of the semiconductor substrate, so that polishing with excellent uniformity can be realized.

According to the semiconductor substrate polishing apparatus of the third aspect of the present invention, since the pad pressing portion has a smooth pressing surface, the polishing pad is not damaged even when pressed by the pad pressing portion. It is possible to prevent the semiconductor substrate from being damaged by the polishing pad.

According to the semiconductor substrate polishing apparatus of the fourth aspect of the present invention, since the pad pressing portion is made of resin, it is hard to be attacked by the polishing agent, so that stable operation can be performed.

According to the semiconductor substrate polishing apparatus of the fifth aspect, since the pressing surface of the pad pressing portion is circular, the pad pressing portion can be easily manufactured.

According to the semiconductor substrate polishing apparatus of the sixth aspect of the present invention, the sum of the amount of pressure applied by the pad pressure unit to the polishing pad and the amount of pressure applied by the semiconductor substrate is almost the same in each region of the polishing pad. Therefore, the entire region of the polishing pad that is in contact with the semiconductor substrate is elastically deformed substantially uniformly, so that the semiconductor substrate can be polished more uniformly.

According to the semiconductor substrate polishing apparatus of the seventh aspect of the present invention, the flatness of the polishing pad is further maintained, so that the pressure received by the semiconductor substrate from the polishing pad during polishing is more uniform over the entire surface of the substrate. Therefore, it is possible to realize polishing with more excellent uniformity.

According to the semiconductor substrate polishing apparatus of the present invention, since the diameter of the pressing surface of the pad pressing portion is larger than the diameter of the first area, the area where the polishing pad is pressed by the semiconductor substrate is Since the pad pressing portion is surely pressed, the semiconductor substrate can be polished more uniformly.

According to the semiconductor substrate polishing apparatus of the ninth aspect, since the amount of deformation of the polishing pad elastically deformed by the pad pressing portion is substantially uniform, the semiconductor substrate is more uniformly polished. be able to.

According to the semiconductor substrate polishing apparatus of the tenth aspect of the present invention, since the polishing pad is constantly pressed by the semiconductor substrate and the pad pressing portion, the entire surface of the polishing pad is always constant. Since the elastic deformation is retained, the semiconductor substrate can be polished more uniformly.

According to the semiconductor substrate polishing apparatus of the eleventh aspect of the present invention, a new abrasive can be supplied from the concave groove to the region of the polishing surface of the polishing pad that is in contact with the pressing surface of the pad pressing portion. The polishing agent deteriorated by polishing the remaining substrate on the polishing pad can be replaced.

According to the semiconductor substrate polishing apparatus of the twelfth aspect of the present invention, since the pad pressing portion can press the polishing pad while rotating with the rotation of the surface plate, friction when the roller presses the polishing pad is increased. Can be reduced, so that more stable polishing can be performed.

According to the semiconductor substrate polishing apparatus of the thirteenth aspect, since the rotation of the surface plate and the rotation of the roller coincide with each other, friction does not occur when the roller presses the polishing pad.

According to the semiconductor substrate polishing apparatus of the fourteenth aspect of the invention, since the pad pressing portion is cylindrical, the pad pressing portion can be easily manufactured.

According to the semiconductor substrate polishing apparatus of the sixteenth aspect of the present invention, since the roller is composed of a plurality of roller members, the occurrence of friction is reduced even if the speed at which the portions of the polishing pad contact each portion of the polishing pad is different. Because you can
More stable polishing can be performed.

According to the semiconductor substrate polishing apparatus of the eighteenth aspect of the present invention, since the region of the polishing pad where the elastic deformation is small can be pressed, the polishing uniformity can be improved.

According to the semiconductor substrate polishing method of the nineteenth aspect of the present invention, since the flatness of the polishing pad is maintained as in the first aspect of the invention, the pressure applied to the semiconductor substrate from the polishing pad during polishing is applied to the semiconductor substrate. Since it becomes uniform over the entire surface, polishing with excellent uniformity can be realized.

According to the semiconductor substrate polishing method of the twentieth aspect of the present invention, since the entire region of the polishing pad in contact with the semiconductor substrate is elastically deformed substantially uniformly, the surface of the polishing pad in contact with the semiconductor substrate is surely secured. Since it becomes flat and the polishing pad polishes the semiconductor substrate with a uniform pressure, more uniform polishing can be realized.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a semiconductor substrate polishing apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the shape of a pad pressing unit in the semiconductor substrate polishing apparatus according to the first to fifth embodiments of the present invention.

FIG. 3 is a schematic cross-sectional view of pad pressing means in a semiconductor substrate polishing apparatus according to a sixth embodiment of the present invention.

FIG. 4 is a schematic perspective view of a semiconductor substrate polishing apparatus according to a seventh embodiment of the present invention.

FIG. 5 is a schematic perspective view showing a shape of a pad pressing portion in a semiconductor substrate polishing apparatus according to seventh to ninth embodiments of the present invention.

FIG. 6 is a schematic perspective view showing a shape of a pad pressing unit in a semiconductor substrate polishing apparatus according to tenth to twelfth embodiments of the present invention.

FIG. 7 is a schematic cross-sectional view for explaining how a polishing pad is pressed and elastically deformed by a pad pressing roller in a semiconductor substrate polishing apparatus according to a seventh embodiment of the present invention.

FIG. 8 is a schematic perspective view of a first conventional semiconductor substrate polishing apparatus.

FIG. 9 is a diagram qualitatively showing a relationship between a polishing pad pressing time, a polishing pad recovery time after pressing and a polishing pad thickness in a conventional semiconductor substrate polishing method and apparatus.

FIG. 10 is a plan view illustrating that in the conventional method and apparatus for polishing a semiconductor substrate, the time when the polishing pad is in contact with the semiconductor substrate and receiving pressure is different.

FIG. 11 is a schematic cross-sectional view of a polishing pad for explaining problems of a conventional semiconductor substrate polishing method and apparatus.

FIG. 12 is a schematic cross-sectional view of a second conventional semiconductor substrate polishing apparatus.

[Explanation of reference numerals] 1 surface plate 1a substrate holding portion 1b rotating shaft 2 polishing pad 3 semiconductor substrate 4 substrate holding head 5 polishing agent 6 polishing agent supply pipe 7 pad pressing means 8A, 8B, 8C, 8D, 8 pad pressing plate 9 rotating shaft 10 plate-like body 11 flexible member 12 sealed space 13 concave groove 14 pad pressing means 15A, 15B, 15C, 15D, 15E, 15F pad pressing roller 16 rotating shaft 21 surface plate 21a substrate holding portion 21b rotating shaft 22 Polishing pad 23 Semiconductor substrate 24 Substrate holding head 25 Polishing agent 26 Polishing agent supply pipe 31 Surface plate 32 Polishing pad 33 Semiconductor substrate 34 Substrate holding head 35 Head body 36 Elastic body 37 Sealed space 38 Gas supply path

Claims (21)

[Claims] 1. A surface plate having a flat surface that moves in a plane,
An elastic polishing pad placed on the flat surface of the surface plate and a semiconductor substrate to be polished are held, and the semiconductor substrate is pressed against the circular first region of the polishing pad while rotating. Pad pressing having a substrate holding means, a polishing agent supplying means for supplying a polishing agent onto the polishing pad, and a pad pressing portion for pressing the second region of the polishing pad to elastically deform the polishing pad. An apparatus for polishing a semiconductor substrate, comprising: 2. The polishing apparatus for a semiconductor substrate according to claim 1, wherein the planar movement is a rotational movement. 3. The semiconductor substrate polishing apparatus according to claim 1, wherein the pad pressing unit has a smooth pressing surface. 4. The polishing apparatus for a semiconductor substrate according to claim 1, wherein the pad pressing portion is made of resin. 5. The polishing apparatus for a semiconductor substrate according to claim 1, wherein the pad pressing unit has a circular pressing surface. 6. The polishing apparatus for a semiconductor substrate according to claim 1, wherein the pad pressing section has an annular pressing surface. 7. The plane movement is rotational movement, and the center of the pressing surface of the pad pressing portion and the center of the first region are concentric with each other about the rotational center of the rotational movement of the surface plate. 7. The polishing apparatus for a semiconductor substrate according to claim 5, which is located. 8. The polishing apparatus for a semiconductor substrate according to claim 7, wherein the pressing surface of the pad pressing unit has a diameter larger than that of the first region. 9. The semiconductor substrate according to claim 1, wherein the pad pressing unit has a trapezoidal pressing surface that expands outward from a center of rotation of the surface plate. Polishing equipment. 10. The polishing apparatus for a semiconductor substrate according to claim 1, wherein the second region is substantially the entire region of the polishing surface of the polishing pad except the first region. 11. The semiconductor substrate according to claim 1, wherein a concave groove for supplying the polishing agent to the polishing surface of the polishing pad is formed on the pressing surface of the pad pressing portion. Polishing equipment. 12. The pad pressing section is composed of a roller having a rotation axis substantially parallel to the flat surface of the surface plate,
The polishing apparatus for a semiconductor substrate according to claim 1, wherein the polishing apparatus is pressed against the second region of the polishing pad and rotates with the movement of the surface plate. 13. The plane motion is a rotary motion, and the roller has a radius ratio of respective portions of a cross section of the roller from a rotation center of a portion of the polishing pad where the respective portions of the cross section of the roller are in contact with each other. 13. The polishing apparatus for a semiconductor substrate according to claim 12, wherein the polishing apparatus has a truncated cone shape equal to the ratio of the distances. 14. The polishing apparatus for a semiconductor substrate according to claim 12, wherein the roller has a cylindrical shape. 15. The semiconductor substrate polishing apparatus according to claim 14, wherein the planar movement is linear movement. 16. The roller according to claim 13, wherein the roller comprises a plurality of roller members arranged coaxially.
16. The semiconductor substrate polishing apparatus according to claim 15. 17. The apparatus for polishing a semiconductor substrate according to claim 12, wherein the second region is wider than the first region. 18. The roller according to claim 13, wherein the roller presses the vicinity of an area of the polishing pad where the time when the polishing pad and the semiconductor substrate are in contact with each other is relatively small. The semiconductor substrate polishing apparatus described in 1. 19. A polishing agent supply step of supplying a polishing agent onto an elastic polishing pad placed on the flat surface of a surface plate having a flat surface that moves in a plane; and a semiconductor substrate being the polishing pad. Substrate polishing step of polishing the semiconductor substrate while pressing the circular first area, and a pad pressing step of pressing the second area of the polishing pad to elastically deform the second area. And a method for polishing a semiconductor substrate. 20. The pressing force for pressing the second area of the polishing pad in the pad pressing step is equal to or more than the pressing force for pressing the first area of the polishing pad in the substrate polishing step. 20. The method for polishing a semiconductor substrate according to claim 19, wherein the polishing method is a semiconductor substrate. 21. The method of polishing a semiconductor substrate according to claim 19, wherein the planar movement is rotational movement.