JP2758152B2 - Device for holding substrate to be polished and method for polishing substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of polishing a substrate by performing chemical mechanical polishing (CMP) for flattening the surface of a substrate such as a semiconductor substrate made of silicon or a liquid crystal substrate, and a method of polishing the substrate. The present invention relates to an apparatus for holding a substrate to be polished, which is used in the above.

[0002]

2. Description of the Related Art Since 1990, in the above-mentioned chemical mechanical polishing technique for semiconductor substrates and liquid crystal substrates, the diameter of the substrate has been increased to 10 cm or more, and the polishing tends to be a single wafer processing. In particular, when polishing a semiconductor substrate, uniform polishing is required over the entire surface of the semiconductor substrate because the rule of a line pattern formed on the semiconductor substrate is extremely fine as 0.5 μm or less. It has become

Hereinafter, a method and an apparatus for polishing a substrate according to a first conventional example will be described with reference to the drawings.

FIG. 9 shows a schematic configuration of a substrate polishing apparatus according to a first conventional example. In FIG. 9, reference numeral 51 denotes a pad mounting portion 51a made of a rigid body having a flat surface and the pad mounting portion 51a. Rotation shaft 51b extending vertically downward from the lower surface of 51a
And a rotating means (not shown) for rotating the rotating shaft 51b, wherein the pad mounting portion 51a of the
A polishing pad 52 having elasticity is attached to the upper surface of the substrate. Above the polishing pad 52, a substrate holding head 54 that holds and rotates the substrate 53 is provided.
Is pressed against the polishing pad 52 while being rotated by the substrate holding head 54. 55 is an abrasive,
The polishing agent 55 is dropped from the polishing agent supply pipe 56 onto the polishing pad 52 by a predetermined amount.

In the substrate polishing apparatus constructed as described above, the substrate holding head 54 is rotated while rotating the platen 51 and the polishing pad 52 to which the abrasive 55 is supplied.
Is pressed against the polishing pad 52, the polished surface of the substrate 53 is polished under pressure and relative speed.

At this time, if there is an uneven portion on the polishing surface of the substrate 53, the contact pressure with the polishing pad 52 is large at the convex portion, so that the relative polishing rate is increased and the polishing is performed. Because of the low contact pressure with, it is hardly polished. Therefore, the unevenness of the polished surface of the substrate 53 is reduced, and the polished surface of the substrate 53 becomes flat. This polishing technique is described in, for example, “January 1994
Monthly Semiconductor World "58-
59 pages and "Solid State Techn"
ology "July. 1992 / Japanese version 32-3
It is introduced on page 7 and so on.

[0007]

However, the first prior art has the following problems which will be described with reference to FIGS.

FIG. 10 is a schematic sectional view showing a polishing method performed by a substrate polishing apparatus according to a first conventional example, and FIG.
FIG. 11 is a schematic cross-sectional view for explaining a problem of the conventional example. Here, a problem in polishing an oxide film 57 formed on a substrate 53 made of silicon and having an uneven surface will be described as an example.

[0009] As shown in FIG.
Is pressed against the polishing pad 52 as described above, while the convex portion of the oxide film 57 is polished because the contact pressure with the polishing pad 52 is large,
Since the contact pressure with the polishing pad 52 is small in the concave portion of the oxide film 57, it is hardly polished, and the unevenness on the surface of the oxide film 57 is reduced, and the surface of the oxide film 57 becomes flat.

In this case, the substrate 53 held by the substrate holding head 51 is pressed against the polishing pad 52 with a uniform pressing force, but as shown in the left diagram of FIG.
11 when the surface of the pad mounting portion 51a is curved, or when the polishing pad 52 is elastically deformed, or in FIG.
If the thickness of the substrate 53 varies as shown in the left diagram of (b), even if the substrate 53 is pressed against the polishing pad 52 with a uniform pressing force, the oxide film 57 and the polishing pad 5
The contact pressure with the contact 2 does not become uniform, and the contact pressure varies. For this reason, the polishing rate is increased in a portion where the contact pressure is high (a portion where the oxide film 57 is in contact with the pad mounting portion 51a or the convex portion of the polishing pad 52 and a portion where the thickness of the substrate 53 is large in the oxide film 57). Since the polishing rate is low in portions where the contact pressure is low (where the oxide film 57 contacts the substrate mounting portion 51a or the concave portion of the polishing pad 52 and where the thickness of the substrate 53 in the oxide film 57 is small), FIG. As shown in the right diagrams of FIGS. 3A and 3B, there is a problem that the polishing amount of the oxide film 57 becomes uneven.

On the other hand, the polishing pad 52 is softened, and as shown in the left diagram of FIG.
2 facilitates elastic deformation in accordance with the unevenness of the pad mounting portion 51a of the surface plate 51 or the polishing pad 52 or the variation in the thickness of the substrate 53, and thereby the unevenness of the pad mounting portion 51a or the polishing pad 52 or the substrate 53 It is possible to reduce the difference in contact pressure caused by the variation in the thickness of the polishing pad to achieve uniform contact pressure. However, when the polishing pad 52 is softened, the elastic deformation of the polishing pad 52 causes the unevenness of the oxide film 57 to become uneven. In order to follow, even the concave portions of the oxide film 57
Therefore, there is a problem that the step on the surface of the oxide film 57 cannot be reduced as shown in the right figure of FIG.

Therefore, as shown in FIG. 12 and described in “August 1993, Nikkei Microdevice”, page 81, the substrate 63 is not affected by the elastic deformation of the polishing pad 62.
A method using a modification of the above has been proposed.

A substrate polishing method and apparatus according to a second conventional example shown in FIG. 12 are as follows. That is, the surface plate 6
A polishing pad 62 having elasticity is stuck on 1. A concave portion 65 is formed below the substrate holding head 64 that holds the substrate 63, and the substrate 63 is fixed to an elastically deformable plate-like elastic body 66 provided in the concave portion 65.
A sealed space 67 is formed by the substrate holding head 64, the elastic body 66, and the substrate 63, and a pressurized gas whose pressure is controlled from a gas supply path 68 is introduced into the sealed space 67. By pressing the substrate 63 held on the elastic body 66 against the polishing pad 62 by the pressurized gas introduced into the sealed space 67 in this manner, the substrate 63 is pressed from the back surface to obtain uniform polishing. Things.

However, in the second conventional example, since the substrate 63 is held by the plate-like elastic body 66, the mechanism for attaching and detaching the substrate 63 is complicated and the substrate 6
3 is complicated.

In view of the above, the present invention enables uniform polishing of a substrate even if the surface plate or polishing pad has irregularities or unevenness in the thickness of the substrate, and also allows the substrate to be attached and detached. The purpose is to simplify the mechanism and work.

[0016]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for holding a substrate to be polished by suction on the substrate holding head, and forming a space between the substrate holding head and the substrate to be polished. The substrate to be polished is pressed against the polishing pad by the pressurized fluid supplied to the space.

A first apparatus for holding a substrate to be polished according to the present invention
A substrate holding device for holding a substrate to be polished and pressing the held substrate to be polished against a polishing pad is intended for a device for holding a substrate to be polished, and is provided so as to be able to advance and retreat with respect to the polishing pad, and a substrate for sucking the substrate to be polished. A substrate holding head having a suction means and a fluid supply path for allowing the pressurized fluid supplied from one end to flow out from the other end, and being fixed to a portion of the substrate holding head surrounding the other end of the fluid supply path, A substrate holding head and an annular seal member forming a space with the substrate to be polished mounted on the polishing pad, wherein the substrate to be polished mounted on the polishing pad is connected to the other end of the fluid supply path. from those pressing the polishing pad by the pressure of the pressurized fluid supplied to the space.

According to the first apparatus for holding a substrate to be polished, the substrate holding head has the substrate suction means for sucking the substrate to be polished. The substrate to be polished held as above can be transferred onto the polishing pad.

The substrate support head includes an annular seal member that forms a space with the substrate to be polished mounted on the polishing pad, and the substrate support head has a fluid supply passage through which pressurized fluid flows out. Since the substrate has such a structure, by supplying the pressurized fluid to the space, the substrate to be polished can be pressed against the polishing pad by the pressure of the pressurized fluid. In this case, the height of the unevenness on the surface of the polishing pad or the surface plate on which the polishing pad is placed is usually easily controlled within several hundred μm. Since it is possible to follow the uneven shape of the surface of the polishing pad, even if a hard polishing pad is used, the contact pressure between the substrate to be polished and the polishing pad becomes uniform.

Further, since the substrate holding head and the annular seal member do not hold the substrate to be polished, if the pressure of the pressurized fluid supplied to the space becomes larger than the pressing force applied to the substrate holding head, the pressure is increased. Since the pressurized fluid pushes up the seal member and the substrate holding head and flows out from between the seal member and the substrate to be polished, the pressure of the pressurized fluid acting on the substrate to be polished is equal to the pressing force applied to the substrate holding head. Since they are substantially equal in a self-aligned manner, the substrate to be polished is pressed against the polishing pad by a stable pressing force.

A first holding device for the substrate to be polished is provided outside the seal member in the substrate holding head;
Preferably it is further provided with a guide member for holding a substrate to be polished is placed on the polishing pad in position
No.

A second apparatus for holding a substrate to be polished according to the present invention
A substrate holding device for holding a substrate to be polished and pressing the held substrate to be polished against a polishing pad is intended for a device for holding a substrate to be polished, and is provided so as to be able to advance and retreat with respect to the polishing pad, and a substrate for sucking the substrate to be polished. A substrate holding head having a suction means and a fluid supply path for allowing the pressurized fluid supplied from one end to flow out from the other end; and a substrate holding head capable of coming into contact with and separating from a portion of the substrate holding head surrounding the other end of the fluid supply path. An annular seal member that forms a space together with the substrate holding head and the substrate to be polished mounted on the polishing pad, wherein the substrate to be polished mounted on the polishing pad is by the pressure of the pressurized fluid from the other end of the fluid supply passage is supplied to the space in which pressing the polishing pad.

According to the second apparatus for holding a substrate to be polished, similarly to the first apparatus for holding a substrate to be polished, the substrate to be polished can be sucked and held, and the substrate to be polished which has been sucked and held can be removed. It can be transferred onto a polishing pad. Also,
By supplying the pressurized fluid to the space, the substrate to be polished can be pressed against the polishing pad by the pressure of the pressurized fluid.

The second device for holding a substrate to be polished is provided outside the portion of the substrate holding head where the seal member is located, and holds the substrate to be polished mounted on the polishing pad to a predetermined position. It is preferable to further include a guide member that holds the position.

[0025] In the holding apparatus of the second substrate to be polished, the seal member is preferably moved on the polished substrate side at the time of polishing is provided a peripheral portion of the substrate to be polished so as to press said polishing pad .

In this case , the seal member is provided so as to be pressed by the pressure of the pressurized fluid supplied to the space from the other end of the fluid supply path to press the peripheral edge of the substrate to be polished against the polishing pad. Being more preferred
No.

The first or second holding device for a substrate to be polished is
It is preferable that the apparatus further comprises means for causing the pressurized fluid supplied to the space to flow out of the space.

A third apparatus for holding a substrate to be polished according to the present invention
A substrate holding device for holding a substrate to be polished and pressing the held substrate to be polished against a polishing pad is intended for a device for holding a substrate to be polished, and is provided so as to be able to advance and retreat with respect to the polishing pad, and a substrate for sucking the substrate to be polished. A substrate holding head having a suction means and a fluid supply path for allowing the pressurized fluid supplied from one end to flow out from the other end, and being fixed to a portion of the substrate holding head surrounding the other end of the fluid supply path, A guide member for holding the substrate to be polished mounted on the polishing pad at a predetermined position, the substrate holding head from the other end of the fluid supply path, the substrate to be polished mounted on the polishing pad, in which the pressure of the guide members and the pressurized fluid supplied to the region surrounded by the substrate to be polished is placed on the polishing pad is pressed against the polishing pad
There is .

According to the third apparatus for holding a substrate to be polished ,
As in the device for holding a substrate to be polished of the first aspect, the substrate to be polished can be sucked and held, and the substrate to be polished sucked and held can be transferred onto the polishing pad.

Further, by supplying a pressurized fluid to a region surrounded by the substrate to be polished placed on the substrate support head, the guide member and the polishing pad, the polished fluid is supplied by the pressure of the pressurized fluid flowing through the region. The substrate can be pressed against the polishing pad.

The first to third substrates to be polished are held by guides.
In the case where the guide member is provided, it is more preferable that the guide member is formed in an annular shape and has a communication passage that allows the inside and the outside of the annular shape to communicate with each other.

In the first to third polishing apparatuses for holding substrates to be polished,
In the substrate holding head, a portion where the other end of the fluid supply path is opened is formed on a flat surface, and a gap between the flat surface and the substrate to be polished placed on the polishing pad is polished. It is preferable that a means for setting the diameter of the substrate to be not more than 1/1000 is further provided.

The method of polishing a substrate according to the present invention is directed to a method of polishing a substrate by polishing a substrate to be polished by pressing the substrate against a rotating polishing pad. The substrate to be polished is suctioned and held upward from below by a substrate holding head. After the above, the first step of transporting the held substrate to be polished above the polishing pad, and releasing the substrate to be polished transported above the polishing pad from the substrate holding head and onto the polishing pad A second step of placing, and a third step of supplying a pressurized fluid onto the substrate to be polished placed on the polishing pad, and pressing the substrate to be polished against the polishing pad with the supplied pressurized fluid. and a process.

According to the substrate polishing method of the present invention, the substrate to be polished is sucked upward from below by the substrate holding head and held, and then the held substrate to be polished is transported above the polishing pad. Is easy to hold and transport onto the polishing pad.

Further, a pressurized fluid can be supplied onto the substrate to be polished placed on the polishing pad, and the substrate to be polished can be pressed against the polishing pad by the pressure of the supplied pressurized fluid.

In the method of polishing a substrate of the present invention , the third step is performed by using the substrate holding head, an annular sealing member fixed to the substrate holding head, and a substrate to be polished placed on the polishing pad. It is preferable to include a step of supplying the pressurized fluid to the space formed.

In the method of polishing a substrate according to the present invention , the third step includes mounting the substrate holding head, an annular seal member provided to be able to contact and separate from the substrate holding head, and the polishing pad. include a step of supplying the pressurized fluid to the space formed by the substrate to be polished is location
Preferred .

In the method of polishing a substrate according to the present invention, when the third step includes a step of supplying the pressurized fluid to the space, the third step includes polishing the substrate holding head by the polishing. The method includes a step of pressing the pad with a predetermined pressing force, and the pressure per unit area of the pressurized fluid supplied to the space is obtained by dividing the predetermined pressing force by the area of the polishing surface of the substrate to be polished. Preferably greater than the available pressure
No.

In this case , the pressure per unit area of the pressurized fluid supplied to the space is at least 1.1 times the pressure obtained by dividing the predetermined pressing force by the area of the polishing surface of the substrate to be polished. And more preferably 2.0 times or less.

In the method of polishing a substrate according to the present invention, when the annular seal member is provided so as to be able to come into contact with and separate from the substrate holding head, a portion of the substrate holding head where the seal member is located is located closer to the substrate holding head. An annular guide member for holding a substrate to be polished mounted on the polishing pad at a predetermined position is also provided on the outside, and the third step includes moving the substrate holding head with respect to the polishing pad. And pressurizing with a predetermined pressing force, wherein the pressure per unit area of the pressurized fluid supplied to the space is a pressure obtained by dividing the predetermined pressing force by the area of the polishing surface of the substrate to be polished. It is preferably smaller than.

In this case , the pressure per unit area of the pressurized fluid supplied to the space is less than 1.0 times the pressure obtained by dividing the predetermined pressing force by the area of the polishing surface of the substrate to be polished. Is more preferable .

In the method of polishing a substrate according to the present invention, the substrate holding head is provided with an annular guide member for holding a substrate to be polished mounted on the polishing pad at a predetermined position. The step of holding the substrate to be polished on the substrate holding head such that the polished surface of the substrate to be polished is located above the lower surface of the guide member, and the third step is a step of holding the substrate holding head Is preferably moved to a position where the polished surface of the substrate to be polished and the lower surface of the guide member are substantially flush with each other.

In the method of polishing a substrate according to the present invention, when the annular sealing member is provided so as to be able to come into contact with and separate from the substrate holding head, the third step includes removing the sealing member from the space. It is preferable that the method further includes a step of pressing the peripheral portion of the substrate to be polished against the polishing pad by pressing with a pressurized fluid supplied to the portion.

In the method of polishing a substrate according to the present invention, a portion of the substrate holding head for holding the substrate to be polished is formed on a flat surface, and the third step is performed on the flat surface and the polishing pad. It is preferable that the method further includes a step of maintaining a distance from the mounted substrate to be polished to one thousandth or more of the diameter of the substrate to be polished.

[0045]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a substrate polishing apparatus and a substrate 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 sectional view of an apparatus for holding a substrate to be polished according to a first embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a rotation made of a rigid body having a flat surface. A possible surface plate, on which an elastic polishing pad 12 is adhered on the upper surface of the surface plate 11.

Above the surface plate 11, a substrate holding device 15A for holding the substrate 13 is disposed. The substrate holding device 15A includes a rotating shaft 16A that is rotated by rotation driving means (not shown) and a rotating shaft 16A. A disk-shaped substrate holding head 17A integrally provided at the lower end;
A ring-shaped seal member 18A made of an elastic body such as silicon rubber fixed to the peripheral portion on the lower surface of A, a ring-shaped guide member 19A fixed to the outside of the seal member 18A on the lower surface of the substrate holding head 17A, The pressurized fluid introduced from one end (upper side in FIG. 1) is
And a fluid flow passage 20A as a fluid supply passage that flows out from the lower side of the above).

Hereinafter, a method of polishing a substrate using the holding apparatus for a substrate to be polished according to the first embodiment will be described with reference to FIG.
This will be described with reference to FIGS.

First, the operation during transport will be described. By moving the substrate 13 or the substrate holding device 15A in the horizontal direction,
After the substrate 13 is positioned below the substrate holding head 17A, the substrate holding head 17A is lowered to bring the substrate holding head 17A and the substrate 13 closer to each other. When the substrate 13 is sucked from the substrate 20A, as shown in FIG.
The substrate is sucked and held by the substrate holding head 17A via 8A. In this state, the substrate holding head 17A is transported in the horizontal direction and moved above the polishing pad 12 on the surface plate 11. This makes it possible to hold and transport the substrate 13 simply and reliably.

Next, the operation during polishing will be described.
The detailed structure of the device for holding a substrate to be polished according to the first embodiment will be described.

As shown in FIG. 2B, the fluid flow passage 20
After the inside of A is set to the atmospheric pressure and the substrate 13 is released and the substrate 13 is placed on the polishing pad 12, a downward pressing force is applied to the rotating shaft 16A. When the substrate 13 made of silicon having a diameter of 8 inches is pressed against the polishing pad 12 with a pressing force of 500 g / cm ² for polishing, the rotating shaft 16A is used.
Is 157 kg. In this case, a pressurized fluid of, for example, 800 g / cm ² of pressurized air or pressurized nitrogen is supplied to the space 21A formed by the substrate holding head 17A, the seal member 18A, and the substrate 13.
Supply from A. In this state, the abrasive 23 containing abrasive grains is used.
Is dropped onto the polishing pad 12, and the platen 11 and the substrate holding head 17A are relatively rotated. By doing so, the polishing surface of the substrate 13 comes into sliding contact with the polishing pad 12, so that the unevenness of the polishing surface of the substrate 13 is alleviated and flattened. The guide member 19A holds the substrate 13 at a predetermined position by preventing the substrate 13 from jumping outward due to centrifugal force caused by rotation.

Here, the height t _A of the space 21A (see FIG. 1) will be examined.

The pressurized fluid supplied from the fluid flow passage 20A to the space 21A presses the substrate 13 from the back surface toward the polishing pad 12, but since the substrate 13 is not bonded to the sealing member 18A, As shown in FIG. 3, the pressurized fluid leaks from the space between the substrate 13 and the seal member 18A to the outside of the space 21A due to the rotation state of the substrate 13, the unevenness of the back surface of the substrate 13, and the like. Height t of space 21A
_{When A} is small, resistance occurs in the flow of the pressurized fluid in the space 21A, and a pressure difference occurs in the space 21A, so that the substrate 13 cannot be pressed uniformly. Therefore, the space the height t _A of the space 21A 2
It is necessary to set such a value that pressure loss hardly occurs in the pressurized fluid flowing through 1A. If the height t _A of the space 21A determined by the thickness of the sealing member 18A, using those low such as water or air (nitrogen) viscosity as a pressurized fluid,
1/1000 the height t _A of the space 21A of the length of the diameter of the substrate 13 (the diagonal in the case of a diameter or square plate in the case of discs)
If the value is set to the above value, preferably a value equal to or more than 2/1000, a pressure difference hardly occurs inside the space 21A. Specifically, by using the sealing member 18A of 0.5mm thick, the height t _A of the space 21A is preferably set to 0.5mm.

As described above, the pressure of the pressurized fluid supplied from the fluid flow passage 20A to the space 21A is larger than the pressing force applied to the rotating shaft 16A.
Is set to about 0.1 mm, the pressure of the pressurized fluid acts as a force for pushing up the substrate holding head 17A, and a gap is generated between the seal member 18A and the substrate 13. As shown by the arrow in FIG. 3, the pressurized fluid flows out of the concave groove 19a of the guide member 19A through the gap between the substrate 13 and the seal member 18A, so that the pressure in the space 21A decreases. . In this way, the pressure of the pressurized fluid in the space 21A coincides with the pressing force applied to the rotating shaft 16A in a self-aligned manner,
Is pressed against the polishing pad 12 by a stable pressing force.

The sum of the thickness of the substrate 13 and the thickness of the seal member 18A is set to be 0.01 or more than the thickness of the guide member 19A.
The polishing surface (lower surface) of the substrate 13 is lower than the lower surface of the guide member 19A by 0.01 to 0.1 mm.
When the guide member 19A protrudes by about 0.1 mm, the guide member 19A and the polishing pad 12 do not come into contact with each other.
It should flow out from the underside of 9A. However, the polishing pad 12 may be elastically deformed or the guide member 1 may be deformed.
When the abrasive flows between the polishing pad 9A and the polishing pad 12, the leaked pressurized fluid may not flow out smoothly from the lower side of the guide member 19A to the outside, and may be trapped inside the guide member 19A. is there. When the pressurized fluid leaked from the space between the substrate 13 and the seal member 18A to the outside of the space 21A is confined inside the guide member 19A, the pressurized fluid enters between the substrate 13 and the polishing pad 12. And pushes the substrate 13 upward.
The force of pressing against the polishing pad 12 decreases. Therefore,
In order to avoid such a situation, the inside and outside of the guide member 19A communicate with the lower surface of the guide member 19A,
A plurality of concave grooves 19a for releasing the pressurized fluid leaked from the space 21A to the outside are provided at appropriate intervals (see FIGS. 4A and 4B).

During polishing, since the substrate 13 is not in contact with the seal member 18A and the guide member 19A, even if the substrate holding head 17A rotates, the substrate 13 rotates following the substrate holding head 17A. Never. Even if the substrate 13 does not rotate, when the surface plate 11 rotates, the surface plate 1
Since the substrate 1 and the substrate 13 rotate relative to each other, the polished surface of the substrate 13 is polished. When it is necessary to rotate the substrate 13 in conjunction with the substrate holding head 17A, as shown in FIG.
4B, a portion corresponding to the orientation flat (orientation flat) is made linear, or as shown in FIG. 4B, a concave portion is provided on the substrate 13 and a convex portion is provided on the guide member 19A. May not be rotated relative to each other. By doing so, it is possible to avoid a situation in which the portion of the back surface of the substrate 13 that contacts the guide member 19A is polished and damaged.

As described above, according to the apparatus for holding a polished substrate or the method for polishing a substrate according to the first embodiment, the pressure of the pressurized fluid supplied to the space 21A causes the substrate 13 to be polished.
Is pressed against the polishing pad 12, so that even if the polishing surface of the polishing pad 12 has irregularities and the substrate 13 is deformed,
Can be pressed against the polishing pad 12 with a uniform pressing force, so that the substrate 13 can be polished uniformly.

Further, since the back surface of the substrate is not directly pressed by the substrate holding head as in the first conventional example, even if foreign substances such as particles adhere to the back surface of the substrate, the substrate 13 can be polished with a uniform pressing force. 12 can be pressed.

Further, since the substrate 13 can be held by the substrate holding head 17A only by sucking the air from the fluid flow passage 20A, the holding and transport of the substrate 13 are easy.

Therefore, according to the apparatus for holding a substrate to be polished or the method for polishing a substrate according to the first embodiment, even if the surface plate 11 or the polishing pad 12 has irregularities or the thickness of the substrate 13 varies, the substrate 13 Can be uniformly polished against
The attachment / detachment and transfer of the substrate 13 are facilitated.

(Second Embodiment) FIG. 5 is a schematic sectional view of an apparatus for holding a substrate to be polished according to a second embodiment of the present invention. In FIG. A possible surface plate, on which a polishing pad 11 having elasticity is stuck on the upper surface of the surface plate 10.

Above the surface plate 10, a substrate holding device 15B for holding the substrate 13 is disposed. The substrate holding device 15B is provided integrally with a rotating shaft 16B at the lower end of the rotating shaft 16B and has a lower surface. A disk-shaped substrate holding head 17B having a concave portion 17a at its bottom, a ring-shaped guide member 19B fixed to the lower peripheral edge of the substrate holding head 17B, and a fluid flow passage 20B.

The second embodiment is different from the first embodiment in that the sealing member 1 provided in the first embodiment is different from the first embodiment.
8A is not provided, and the fluid dispersion plate 24B that distributes the pressurized fluid flowing through the fluid flow passage 20B to the concave portion 17a of the substrate holding head 17B through the dispersion holes 24a and supplies the fluid to the space 21B is provided by the substrate holding head 17B. It is provided integrally with the head 17B.

In the first embodiment, the space 2
In the second embodiment, the pressure of the pressurized fluid supplied to the rotating shaft 16A is self-aligned with the pressure of the pressurized fluid supplied to the rotary shaft 16A. It is constantly discharged to the outside and the space 21
B, the pressure of the pressurized fluid flowing through the rotating shaft 16B is self-aligned with the pressing force applied to the rotating shaft 16B, and the substrate 13 is polished by the pressure of the flowing pressurized fluid matching the pressing force applied to the rotating shaft 16A. 12 is a mechanism for pressing the same.

Hereinafter, a polishing method using the substrate polishing apparatus according to the second embodiment will be described with reference to FIGS. 6 (a) and 6 (b).

First, the operation during transport will be described. By moving the substrate 13 or the substrate holding device 15B in the horizontal direction,
After the substrate 13 is positioned below the substrate holding head 17B, the substrate holding head 17B is lowered to bring the substrate holding head 17B and the substrate 13 close to each other.
When the air in the concave portion 17a of the substrate holding head 17B is sucked from 0B, the pressure in the lower space of the fluid dispersion plate 24B is reduced, and as shown in FIG.
4B, and is securely held by the substrate holding head 17B. In this state, the substrate holding head 17B is moved in the horizontal direction to transport the substrate 13 above the polishing pad 12 on the surface plate 11. This makes it possible to easily and reliably hold and transport the substrate 13.

Next, the operation during polishing will be described.
A detailed structure of the device for holding a substrate to be polished according to the second embodiment will be described.

The interior of the fluid flow passage 20B and thus the recess 17a of the substrate holding head 17B is released to the atmospheric pressure, and
After placing 3 on the polishing pad 12, a downward pressing force is applied to the rotating shaft 16B. When the substrate 13 made of silicon having a diameter of 8 inches is pressed against the polishing pad 12 with a pressing force of 500 g / cm ² for polishing, the rotating shaft 1
The pressing force applied to 6B is 157 kg. In this case, the space 21B formed by the substrate holding head 17B, the guide member 19B, and the substrate 13 has, for example, 600 g / cm.
Supply ² pressurized fluids. In this state, the platen 11 and the substrate holding head 17B are relatively rotated while an abrasive containing abrasive grains is dropped on the polishing pad 12. In this way, the polishing surface of the substrate 13 comes into sliding contact with the polishing pad 12, so that the unevenness of the polishing surface is reduced and the polishing surface is flattened. As in the first embodiment, the guide member 19B prevents the substrate 13 from jumping outward due to centrifugal force caused by rotation, and differs from the first embodiment together with the substrate holding head 17B, the fluid dispersion plate 24B, and the substrate 13. The space 21B is formed.

Here, the height t _B of the space 21B will be considered.

The pressurized fluid supplied to the space 21B from the fluid flow passage 20B flows through the gap between the substrate 13 and the guide member 19B and the concave groove 19a of the guide member 19B, and flows out of the substrate 13 to the outside. Although it pressed against the polishing pad 12 from the back, if a small height t _B of the space 21B is a pressure difference is generated inside the space 21B to cause resistance to the flow of fluid in the space portion 21B Therefore, the substrate 13 cannot be pressed uniformly. Therefore, it is necessary to set the height t _B of the space 21B to a value such that the pressure drop in the pressurized fluid flowing through the space portion 21B hardly occurs. The height t _B of the space portion 21B is the guide member 1
Determined by the difference between the thickness of the substrate 9B and the thickness of the substrate 13, and when using a low-viscosity fluid such as water or air (nitrogen) as the pressurized fluid, a value of 1/1000 or more of the diameter of the substrate 13 is used. , Preferably set to a value of 2/1000 or more,
There is almost no pressure difference inside the space 21B. Specifically, the height t _B of the space 21B is preferably set to 0.5 mm.

The dispersion holes 24 formed in the fluid dispersion plate 24B
It is preferable that the diameter, the number and the arrangement of a are appropriately set so that the substrate 13 can be uniformly pressurized by the pressurized fluid supplied from the dispersion holes 24a to the space 21B. The arrangement of the dispersion holes 24a is concentric. Preferably, the shape is radial. Further, a porous plate may be used as the fluid dispersion plate 24B.

As described above, the pressure of the pressurized fluid supplied from the fluid flow passage 20B to the space 21B is greater than the pressing force applied to the rotating shaft 16B.
When the gap between the guide member 19B and the guide member 19B is set to about 0.1 mm, the pressurized fluid passes through the gap between the substrate 13 and the guide member 19B as shown by the arrow in FIG. Flows out of the concave groove 19a of the member 19B to the outside,
As a result, the pressure of the space 21B decreases, so that the pressure of the pressurized fluid flowing through the space 21B coincides with the pressing force applied to the rotating shaft 16B in a self-aligned manner, and the substrate 13 is stably pressed. It is pressed against the polishing pad 12.

The space portion 21B extends from the fluid flow passage 20B.
Is greater than the pressing force applied to the rotating shaft 16B, the pressure of the pressurized fluid acts as a force to push the substrate holding head 17 upward. There is a gap between the polishing pad 12 and the pressurized fluid flows out through the gap.
However, when the polishing pad 12 is elastically deformed or an abrasive flows between the guide member 19B and the polishing pad 12, the pressurized fluid cannot flow out smoothly from the lower side of the guide member 19B to the outside. It may be trapped inside 19B. In such a case, as described above, the pressurized fluid penetrates between the substrate 13 and the polishing pad 12 to push the substrate 13 upward, and the force for pressing the substrate 13 against the polishing pad 12 decreases. Therefore, in order to avoid such a situation, the lower surface of the guide member 19B has the same concave groove 1 as in the first embodiment.
9a are provided at a plurality of locations at appropriate intervals.

As described above, according to the apparatus for holding a substrate to be polished or the method for polishing a substrate according to the second embodiment, the concave groove of the guide member 19 is supplied to the space 21B from the dispersion holes 24a of the fluid dispersion plate 24B. The substrate 13 is pressed against the polishing pad 12 by the pressure of the pressurized fluid flowing out of the polishing pad 19a.
Is deformed, the polishing pad 1 is pressed against the substrate 13 with a uniform pressing force.
2, the substrate 13 can be uniformly polished.

Further, even if foreign substances such as particles adhere to the back surface of the substrate, the substrate 13 can be pressed against the polishing pad 12 with a uniform pressing force.

Further, the dispersion holes 24a of the fluid dispersion plate 24B
Since the substrate 13 can be sucked to the substrate holding head 17B only by sucking the substrate 13 from the substrate 13, the holding and transport of the substrate 13 are easy.

Therefore, according to the apparatus for holding a substrate to be polished or the method for polishing a substrate according to the second embodiment, even if the surface plate 11 or the polishing pad 12 has irregularities or the thickness of the substrate 13 varies, the substrate 13 Can be uniformly polished against
The attachment / detachment and transfer of the substrate 13 are facilitated.

FIG . 7 is a schematic sectional view of a device for holding a substrate to be polished according to a third embodiment of the present invention.
Reference numeral 10 denotes a rotatable surface plate made of a rigid body having a flat surface, and an elastic polishing pad 11 is attached to the upper surface of the surface plate 10.

Above the surface plate 10, a substrate holding device 15C for holding the substrate 13 is arranged. The substrate holding device 15C is provided integrally with a rotating shaft 16C and a lower end of the rotating shaft 16C. A disk-shaped substrate holding head 17C having a concave portion 17a on the lower surface, and a concave portion 17 of a substrate holding head 17B.
a, a fluid dispersion plate 24C having a dispersion hole 24a provided integrally with the substrate holding head 17B, a ring-shaped guide member 19C fixed to the lower peripheral edge of the substrate holding head 17C, and an inner side of the guide member 19C. A ring-shaped seal member 18C made of an elastic material provided so as to be vertically movable,
And a fluid flow passage 20C.

The third embodiment is different from the second embodiment in that a seal member 18C is provided inside a guide member 19C so as to be vertically movable. In this case, the height of the concave portion 17a of the substrate holding head 17B is equal to that of the sealing member 18C.
Is set to be larger than the height.

In the first and second embodiments, the pressure of the pressurized fluid supplied to the spaces 21A and 21B is matched in self-alignment with the pressing force applied to the substrate holding heads 17A and 17B. Substrate holding heads 17A, 17B
Is a mechanism that presses the substrate 13 against the polishing pad 12 by the pressure of the pressurized fluid that matches the pressing force applied to the substrate. However, in the third embodiment, the pressure of the pressurized fluid supplied to the space 21C is reduced by the substrate holding pressure. This is a mechanism in which the substrate 13 is pressed against the polishing pad 12 by the pressure of the pressurized fluid supplied to the space 21C at a pressure equal to the pressing force applied to the head 17C.

FIG. 8 shows a method of polishing a substrate by using the substrate holding apparatus according to the third embodiment.
This will be described with reference to FIGS.

First, the operation during transport will be described. By moving the substrate 13 or the substrate holding device 15C in the horizontal direction,
After the substrate 13 is positioned below the substrate holding head 17C, the substrate holding head 17C is lowered to bring the substrate holding head 17C and the substrate 13 close to each other.
When the air in the concave portion 17a of the substrate holding head 17C is sucked from 0C, the pressure in the lower space of the fluid dispersion plate 24C is reduced, and therefore, as shown in FIG.
4C, and is reliably held by the substrate holding head 17C. In this case, as the pressure in the concave portion 17a of the substrate holding head 17C is reduced, the seal member 18C moves upward away from the substrate 13. In this state, the substrate holding head 17C is moved in the horizontal direction to transfer the substrate 13 above the polishing pad 12. This makes it possible to hold and transport the substrate 13 simply and reliably.

Next, the operation during polishing will be described.
A detailed structure of the substrate holding device according to the third embodiment will be described.

The suction from the fluid flow passage 20C is released, and the concave portion 17a of the substrate holding head 17C and the space portion 21C are released.
After the pressure is adjusted to the atmospheric pressure, a downward pressing force is applied to the rotating shaft 16C. The substrate 13 made of silicon having a diameter of 8 inches is applied to the polishing pad 12 at a pressure of 500 g / cm ^2.
When polishing by pressing against the rotating shaft 16C, the pressing force applied to the rotating shaft 16C is 157 kg.
Apply kg force. In this case, for example, 5
A pressurized fluid of 00 g / cm ² is supplied. In this state, while dropping an abrasive containing abrasive grains onto the polishing pad 12,
The platen 11 and the substrate holding head 17C are relatively rotated.
In this way, as shown in FIG.
Is in sliding contact with the polishing pad 12, so that the unevenness of the polished surface of the substrate 13 is alleviated and flattened. The seal member 18C forms a space 21C together with the fluid dispersion plate 24C and the substrate 13, and the guide member 19B has a function of preventing the substrate 13 from jumping out due to centrifugal force accompanying rotation.

Here, the relationship between the pressing force applied to the rotating shaft 16C and the pressure of the pressurized fluid supplied to the space 21C will be examined. The pressing force applied to the rotating shaft 8 (the space 2
When the guide member 18 presses the polishing pad 12, the polishing pad 12 can be elastically deformed in advance, and is larger than the pressure of the pressurized fluid supplied to 1 C × the area of the substrate 13. 13, the pressure of the pressurized fluid supplied to the space 21C is (the pressing force applied to the rotating shaft 16C) ÷ (the area of the substrate 13). 1.0
The pressure is preferably less than twice, and more preferably the pressing force applied to the guide member 18 is substantially equal to the pressure of the pressurized fluid.

Next, the height t _C of the space 21C will be discussed.

Since the recess 17a of the substrate holding head 17C and the space 21C communicate with each other through the dispersion hole 24a of the fluid dispersion plate 24C, the pressure of the recess 17a is equal to the pressure of the space 21C, but the seal member 18C Since it is not fixed to the substrate holding head 17 </ b> C, the space 2 may vary depending on the rotation state of the substrate 13 during polishing and the unevenness of the back surface of the substrate 13.
The pressurized fluid supplied to 1C leaks out of the gap between the seal member 18C and the substrate 13. When the height t _C of the space 21C is small, a resistance is generated in the flow of the fluid in the space 21C, and a pressure difference is generated inside the space 21C, so that the substrate 13 cannot be pressed uniformly. For this reason, the height t _C of the space 21C is
It is necessary to set such a value that pressure loss hardly occurs in the pressurized fluid flowing through C. The height t _C of the space portion 21C is determined by the difference between the thickness of the guide member 19C and the thickness of the substrate 13, and when a low-viscosity fluid such as water or air (nitrogen) is used as the pressurized fluid, the substrate 13 1/10 of the length of the diameter of
When it is set to a value of 00 or more, preferably a value of 2/1000 or more, a pressure difference hardly occurs inside the space 21C. Specifically, the height t _C of the space 21C is set to 0.5 m
m is preferable.

The dispersion holes 24 formed in the fluid dispersion plate 24C
It is preferable that the diameter, the number, and the arrangement of “a” are appropriately set so that the substrate 13 can be uniformly pressurized by the pressurized fluid supplied from the dispersion holes 24a to the space 21C, and the arrangement of the dispersion holes 24a is concentric. Preferably, the shape is radial. Further, a porous plate may be used as the fluid dispersion plate 24C.

As described above, the lower surface of the guide member 19C and the rear surface of the substrate 13 are at the same height, and the seal member 18C is pressed downward by the pressurized fluid supplied to the space 21C. Therefore, the lower surface of the seal member 18C is in contact with the polished surface of the substrate 13. For this reason, if the weight of the seal member 18 is neglected, and the area of the upper surface of the seal member 18 is equal to the area of the lower surface, the peripheral portion of the substrate 13 is polished by the same pressing force as the central portion of the substrate 13. Will be pressed.

Since the seal member 18 is pressurized upward by the pressurized fluid supplied to the space 21C, the pressurized fluid easily leaks from the contact surface between the seal member 18 and the substrate 13. It is preferable that the area of the upper surface be larger than the area of the lower surface. However, in practice, the peripheral portion of the substrate 13 is pressed with a greater force by the weight of the sealing member 18 than the central portion, so that the sealing member 1
The degree of making the area of the upper surface of 8 larger than the area of the lower surface may be small.

Since the substrate 13 and the seal member 18C are only in contact with each other, the pressurized fluid in the space 21C is not applied to the substrate 13C.
And leaks from between the seal member 18C. In this case, unlike the first and second embodiments, since the pressing force applied to the rotating shaft 16C is slightly larger than the pressure of the pressurized fluid supplied to the space 21C, the pressurized fluid leaking from the space 21C The substrate holding head 17C and the guide member 19C
Is not pushed upward, and the leaked pressurized fluid does not flow out of the gap between the guide member 19C and the polishing pad 12. When the leaked pressurized fluid is confined by the guide member 19C, the pressurized fluid penetrates between the substrate 13 and the polishing pad 12 to push up the substrate 13 and reduce the force for pressing the substrate 13 against the polishing pad 12. In order to avoid this situation, the substrate 13 and the sealing member 1
While the gap with 8C is set to about 0.1 mm,
It is preferable to provide a plurality of concave grooves 19a similar to those in the first embodiment at appropriate intervals on the lower surface of the guide member 19C.

As described above, according to the apparatus or method for polishing a substrate to be polished according to the third embodiment, the pressure of the pressurized fluid supplied to the space 21C from the dispersion holes 24a of the fluid dispersion plate 24C. Substrate 13 by polishing pad 1
2, the substrate 13 can be pressed against the polishing pad 12 with a uniform pressing force even if the polishing surface of the polishing pad 12 has irregularities and the substrate 13 is deformed.
3 can be uniformly polished.

Further, even if foreign substances such as particles adhere to the back surface of the substrate 13, the semiconductor substrate 13 can be pressed against the polishing pad 12 with a uniform pressing force.

Further, the dispersion holes 24a of the fluid dispersion plate 24C are formed.
Since the substrate 13 can be sucked to the substrate holding head 17C only by sucking the substrate 13 from the substrate 13, the holding and transport of the substrate 13 are easy.

Therefore, according to the apparatus for holding a substrate to be polished or the method for polishing a substrate according to the third embodiment, even if the surface plate 11 or the polishing pad 12 has irregularities or the thickness of the substrate 13 varies, the substrate 13 Can be uniformly polished against
The attachment / detachment and transfer of the substrate 13 are facilitated.

[0097]

According to the first or second apparatus for holding a substrate to be polished, the substrate to be polished can be sucked and held, and the held substrate to be polished can be transferred onto the polishing pad. Thus, the attachment and detachment and transfer of the substrate to be polished can be performed easily and reliably. Further, the substrate to be polished can be pressed against the polishing pad by the pressing force of the pressurized fluid supplied to the space formed by the substrate supporting head, the annular sealing member, and the substrate to be polished placed on the polishing pad. Therefore, even if the polishing pad has irregularities or the substrate to be polished is deformed, or even if foreign matter such as particles adheres to the back surface of the substrate to be polished, the substrate to be polished can be stably and uniformly pressed. Can be pressed against the polishing pad, so that the substrate to be polished can be uniformly polished.

The first or second holding device for the substrate to be polished is
When provided with a guide member provided on the outer side of the seal member in the substrate holding head, it is possible to securely hold the substrate to be polished is placed on the polishing pad in place.

In the second apparatus for polishing a substrate to be polished,
When the rule member moves toward the substrate to be polished during polishing and presses the peripheral portion of the substrate to be polished against the polishing pad, it is possible to avoid a situation where the peripheral portion of the substrate to be polished rises during polishing.

In this case, when the sealing member is pressed by the pressure of the pressurized fluid supplied to the space and presses the peripheral edge of the substrate to be polished against the polishing pad, the peripheral edge of the substrate to be polished is the same as other portions. Since the pressing target can be pressed against the polishing pad, the substrate to be polished can be polished more uniformly.

The first or second holding device for the substrate to be polished is
When a means is provided for allowing the pressurized fluid supplied to the space to flow out of the space, the pressure of the pressurized fluid supplied to the space becomes greater than the pressing force applied to the substrate holding head. In, even if the polishing pad is elastically deformed or the abrasive flows between the guide member and the polishing pad, the pressurized fluid smoothly flows out to the outside,
It is possible to avoid a situation where the pressurized fluid enters between the polishing target substrate and the polishing pad and pushes the polishing target substrate upward.

According to the third apparatus for holding a substrate to be polished, the substrate to be polished can be attracted and held, and the held substrate to be polished can be transferred onto the polishing pad. Attaching and detaching and transport can be performed easily and reliably. Further, the substrate to be polished is pressed against the polishing pad by the pressure of the pressurized fluid supplied to the region formed by the substrate support head, the annular sealing member and the substrate to be polished placed on the polishing pad and flowing through the region. Therefore, even if the polishing pad has irregularities or the substrate to be polished is deformed, or even if foreign matter such as particles adheres to the back surface of the substrate to be polished, it can be stably and uniformly pressed. Since the substrate to be polished can be pressed against the polishing pad, the substrate to be polished can be uniformly polished.

In the first to third apparatuses for holding substrates to be polished,
Te, the guide member has a communicating path for communicating the inside and the outside of the annular together is formed in a ring shape, it is possible to form a space portion substrate holding head, the guide member and the substrate to be polished, The substrate to be polished can be uniformly pressed by the pressurized fluid supplied to the space, and when the pressure of the pressurized fluid in the space becomes too large, the pressurized fluid passes through the communication passage. It can flow out of the guide member.

In the first to third apparatuses for holding substrates to be polished,
The portion of the substrate holding head where the other end of the fluid supply path is open is a flat surface, and the distance between the flat surface and the substrate to be polished placed on the polishing pad is 100 mm of the diameter of the substrate to be polished.
When a means for setting the pressure to 1/0 or more is provided, a resistance is generated in the flow of the fluid when the pressurized fluid flows between the substrate to be polished and the substrate holding head, and the fluid pressurizes the substrate to be polished. Since a pressure difference can be avoided, the substrate to be polished can be more uniformly polished.

According to the substrate polishing method of the present invention, the substrate to be polished is sucked upward from below by the substrate holding head and held, and then the held substrate to be polished is transported above the polishing pad. Is easy to hold and transport onto the polishing pad. In addition, a pressurized fluid is supplied onto the substrate to be polished placed on the polishing pad, and the substrate to be polished is pressed against the polishing pad by the supplied pressurized fluid. The substrate to be polished can be pressed against the polishing pad with a uniform pressing force even if the substrate is deformed or foreign substances such as particles adhere to the back surface of the substrate to be polished. Can be polished.

Third Embodiment in the Substrate Polishing Method of the Present Invention
The step of supplying a pressurized fluid to a space formed by the substrate holding head, the annular seal member fixed to the substrate holding head, and the substrate to be polished mounted on the polishing pad includes: Since the substrate can be pressed against the polishing pad by the pressurized fluid supplied to the space,
The substrate to be polished can be more uniformly polished.

The third step in the substrate polishing method of the present invention.
Degree is, the substrate holding head, supplying a pressurized fluid in a space portion formed by the substrate to be polished is placed on the separable therefrom provided an annular sealing member and the polishing pad relative to the substrate holding head to include, since it is possible to press the polishing pad by the pressurized fluid supplied to the substrate to be polished in the space portion, it is possible to polishing the substrate more uniformly.

Third Embodiment of the Substrate Polishing Method of the Present Invention
In the process, the pressure per unit area of the pressurized fluid supplied to the space is larger than the pressure obtained by dividing the predetermined pressing force applied to the substrate holding head by the area of the polishing surface of the substrate to be polished, Since the pressurized fluid presses the substrate to be polished while flowing out of the space, the pressure difference of the pressurized fluid acting on the substrate to be polished is eliminated, so that the substrate to be polished can be more uniformly polished. it can.

In the method of polishing a substrate of the present invention, the pressure per unit area of the pressurized fluid supplied to the space is determined by dividing the predetermined pressing force by the area of the polishing surface of the substrate to be polished. If and it is 2.0 times or less at 1.1 times or more,
The pressurized fluid acting on the substrate to be polished does not flow too much because the pressurized fluid hardly flows out of the space, or conversely, the flow speed does not become too large because the pressurized fluid flows out of the space too much. Since the pressure difference is further reduced, the substrate to be polished can be more uniformly polished.

In the method of polishing a substrate of the present invention, if an annular guide member is provided outside the portion of the substrate holding head where the seal member is located, the substrate to be polished is positioned at a predetermined position on the polishing pad during polishing. While being securely held, the pressure per unit area of the pressurized fluid supplied to the space is obtained by dividing the predetermined pressing force applied to the substrate holding head by the area of the polished surface of the substrate to be polished. Since the pressure is smaller than the pressure, it is possible to avoid a situation in which the pressurized fluid enters between the substrate to be polished and the polishing head and pushes up the seal member and the substrate to be polished which are provided to be able to contact and separate from the substrate holding head.

In the method of polishing a substrate of the present invention, the pressure per unit area of the pressurized fluid supplied to the space is determined by dividing the predetermined pressing force by the area of the polishing surface of the substrate to be polished. If it is less than and 1.0 times 0.8 times or more,
It is possible to avoid a situation where the pressure of the pressurized fluid supplied to the space is increased and the seal member and the substrate to be polished are pushed up, and the pressure applied to the substrate holding head is larger than the pressure of the pressurized fluid. It is possible to avoid a situation in which the guide member is pressed too strongly against the polishing pad.

In the method of polishing a substrate according to the present invention, if an annular guide member is provided outside the portion of the substrate holding head where the seal member is located, the substrate to be polished is positioned at a predetermined position on the polishing pad during polishing. When the third step includes moving the substrate holding head to a position where the polished surface of the substrate to be polished and the lower surface of the guide member are substantially flush with each other, the third step is supplied to the space. Since the pressing force applied to the substrate to be polished by the pressurized fluid is substantially equal to the pressing force applied to the guide member, the pressurized fluid supplied to the space portion polishes the substrate to be polished without flowing out from the space portion. Can be pressed against the pad.

Third Embodiment of the Substrate Polishing Method of the Present Invention
The process includes a step of pressing the peripheral portion of the substrate to be polished against the polishing pad by pressing the seal member with the pressurized fluid supplied to the space portion, to avoid a situation in which the peripheral portion of the substrate to be polished rises during polishing. Can be.

In the method of polishing a substrate according to the present invention, the portion of the substrate holding head for holding the substrate to be polished is formed on a flat surface, and the third step is performed by setting the substrate on the polishing surface and the flat surface. The distance from the polished substrate is set to 1 of the diameter of the polished substrate.
When the step of maintaining the pressure at 1/000 or more is included , resistance is generated in the flow of the fluid when the pressurized fluid flows between the substrate to be polished and the substrate holding head, and a pressure difference is generated between the fluid that pressurizes the substrate to be polished. Can be avoided, so that the substrate to be polished can be more uniformly polished.

As described above, the object to be polished according to the present invention is
According to a substrate holding device or a substrate polishing method, a substrate to be polished is pressed against a polishing pad by a stable pressing force, and stable polishing can be performed, and the polishing pad and a surface plate on which the polishing pad is mounted are mounted. Even if there are irregularities or variations in the thickness of the substrate to be polished, uniform polishing can be performed on the substrate to be polished, and the attachment / detachment and transfer of the substrate to be polished can be realized with a simple structure. it can.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an apparatus for holding a substrate to be polished according to a first embodiment of the present invention.

FIGS. 2A and 2B are schematic cross-sectional views illustrating respective steps of a polishing method using the holding apparatus for a substrate to be polished according to the first embodiment.

FIG. 3 is a schematic sectional view illustrating an operation of a polishing step in a polishing method using the holding device for a substrate to be polished according to the first embodiment.

FIGS. 4A and 4B are bottom views of a guide member in the holding device for a substrate to be polished according to the first embodiment.

FIG. 5 is a schematic sectional view of an apparatus for holding a substrate to be polished according to a second embodiment of the present invention.

FIGS. 6A and 6B are schematic cross-sectional views illustrating respective steps of a polishing method using a holding device for a substrate to be polished according to the second embodiment.

FIG. 7 is a schematic sectional view of an apparatus for holding a substrate to be polished according to a third embodiment of the present invention.

FIGS. 8A and 8B are schematic cross-sectional views illustrating respective steps of a polishing method using a holding device for a substrate to be polished according to the third embodiment.

FIG. 9 is a schematic perspective view of a substrate polishing apparatus according to a first conventional example.

FIG. 10 is a schematic sectional view of a polishing method performed by the substrate polishing apparatus according to the first conventional example.

FIGS. 11A to 11C are schematic cross-sectional views illustrating problems in a polishing method performed by the substrate polishing apparatus according to the first conventional example.

FIG. 12 is a schematic sectional view of a substrate polishing apparatus according to a second conventional example.

[Explanation of symbols]

 Reference Signs List 11 surface plate 12 polishing pad 13 substrate 15A, 15B, 15C substrate holding device 16A, 16B, 16C rotation axis 17A, 17B, 17C substrate holding head 18A, 18B, 18C sealing member 19A, 19B, 19C guide member 19a concave groove 20A, 20B, 20C Fluid flow passage 21A, 21B, 21C Space 23 Abrasive 24B, 24C Fluid dispersion plate 24a Dispersion hole

Claims (10)

(57) [Claims] An apparatus for holding a substrate to be polished and pressing the held substrate to be polished against a polishing pad, wherein the holding apparatus is provided so as to be able to advance and retreat with respect to the polishing pad. A substrate holding head having a substrate suction means for sucking and a fluid supply path for allowing the pressurized fluid supplied from one end to flow out from the other end; fixed to a portion of the substrate holding head surrounding the other end of the fluid supply path. A sealing member forming a space together with the substrate holding head and the substrate to be polished placed on the polishing pad, wherein the substrate to be polished placed on the polishing pad is by the pressure of the pressurized fluid supplied to the space from the other end pressed against the polishing pad, the pressure supplied to the space from the other end of said fluid supply passage
The pressure of the fluid is determined by the pressing force applied to the substrate holding head.
Is greater than the pressure of the pressurized fluid.
Is pushed up together with the substrate holding head by
Forming a gap between the sealing member and the substrate to be polished;
The pressurized fluid flows out from the space through the space
A device for holding a substrate to be polished. 2. An apparatus for holding a substrate to be polished, which holds the substrate to be polished and presses the held substrate to be polished against a polishing pad, wherein the apparatus is provided so as to be capable of moving back and forth with respect to the polishing pad. A substrate holding head having a substrate suction means for sucking and a fluid supply path for allowing the pressurized fluid supplied from one end to flow out from the other end; and a portion in contact with a portion of the substrate holding head surrounding the other end of the fluid supply path. A seal member that is provided so as to be detachable and forms a space with the substrate holding head and the substrate to be polished mounted on the polishing pad, and the substrate to be polished mounted on the polishing pad is the pressed against the polishing pad by the pressure of the pressurized fluid supplied to the space from the other end of said fluid supply passage, the sealing member, the space from the other end of said fluid supply passage
Polished by the pressure of the pressurized fluid supplied to the part
By moving to the substrate side, the peripheral edge of the substrate to be polished is
A device for holding a substrate to be polished, wherein the device is pressed against a polishing pad . 3. The seal in the substrate holding head.
Provided outside the member, while holding the substrate to be polished placed on the polishing pad at a predetermined position,
3. The apparatus for holding a substrate to be polished according to claim 1 , further comprising a guide member having a communication path that allows communication between the substrate and the outside . 4. 4. A portion of the substrate holding head where the other end of the fluid supply path opens is formed as a flat surface,
The apparatus according to claim 1 , further comprising a unit configured to set a distance between the flat surface and the substrate to be polished mounted on the polishing pad to be equal to or more than 1/1000 of a diameter of the substrate to be polished.
3. The device for holding a substrate to be polished according to 1 or 2 . 5. The seal member is made of an elastic body.
The holding of the substrate to be polished according to claim 1 or 2,
apparatus. 6. A polishing method for a substrate, wherein a substrate to be polished is pressed against a polishing pad to polish the substrate.
It has a fluid supply path for letting out the supplied pressurized fluid from the other end.
A substrate holding head and a front of the substrate holding head
A seal fixed to a portion surrounding the other end of the fluid supply passage
The member and the substrate to be polished placed on the polishing pad
Thus, a space is formed from the other end of the fluid supply passage.
A first step of supplying a pressurized fluid, and pressing the substrate holding head against the polishing pad by a predetermined pressure.
A second step of pressing with pressure, and pressurization supplied to the space from the other end of the fluid supply path
The substrate to be polished is pressed against the polishing pad by the pressure of the fluid.
And the pressurization supplied to the space from the other end of the fluid supply path.
When the pressure of the fluid is greater than the predetermined pressure,
The substrate is held on the sealing member by the pressure of the pressurized fluid.
The sealing member and the substrate to be polished are pushed up together with the head.
To form a gap between the pressurized fluid through the gap
And a fourth step of flowing out from the space to the outside . 7. A pressure per unit area of the pressurized fluid supplied to the space is larger than a pressure obtained by dividing the predetermined pressing force by an area of a polishing surface of a substrate to be polished. The method for polishing a substrate according to claim 6 . 8. The pressure per unit area of the pressurized fluid supplied to the space is at least 1.1 times the pressure obtained by dividing the predetermined pressing force by the area of the polishing surface of the substrate to be polished. The method for polishing a substrate according to claim 7 , wherein the ratio is 2.0 times or less. 9. Polishing is performed by pressing a substrate to be polished against a polishing pad.
A method of polishing a substrate to be polished, The polishing pad is provided to be able to advance and retreat,
It has a fluid supply path for letting out the supplied pressurized fluid from the other end.
A substrate holding head and a front of the substrate holding head
The fluid supply path is provided so as to be able to contact and separate from the part surrounding the other end
Sealing member, and the polishing target mounted on the polishing pad.
The fluid supply path in the space formed by the polishing substrate
A first step of supplying a pressurized fluid from the other end; The substrate holding head is pressed against the polishing pad by a predetermined amount.
A second step of pressing with pressure; Pressurization supplied to the space from the other end of the fluid supply path
The substrate to be polished is pressed against the polishing pad by the pressure of the fluid.
And moving the seal member toward the substrate to be polished.
Pressing the peripheral portion of the substrate to be polished against the polishing pad.
3. A method of polishing a substrate, comprising:
Law. 10. A portion of the substrate holding head for holding a substrate to be polished is formed on a flat surface. In the third step, the flat surface and the substrate to be polished placed on the polishing pad are formed. Is set to 100 times the diameter of the substrate to be polished.
A step of maintaining the value at least 1/0
10. The method for polishing a substrate according to claim 6 or 9 .