TW202116477A - Wafer polishing head can improve the productivity of the wafer polishing device and realize the high efficiency of the polishing step - Google Patents

Abstract

The invention provides a wafer polishing head, which can improve the productivity of the wafer polishing device and realize the high efficiency of the polishing step. The wafer polishing device includes: a chuck mechanism with a rubber chuck and a rigid chuck; a first pressure adjustment mechanism capable of supplying air to the vicinity of the rubber chuck; and a second pressure adjustment mechanism supplying air to the vicinity of the rigid chuck. The wafer polishing apparatus can switch the processing method by switching the air supply of the first pressure adjustment mechanism and the air supply of the second pressure adjustment mechanism. Accordingly, a wafer polishing head having both the functions of a rubber chuck and a chuck mechanism of a rigid chuck in the chuck mechanism can be obtained. Therefore, there is no need to provide two wafer polishing heads, capable of enhancing the productivity of the wafer polishing apparatus. In addition, there is no need to replace the wafer polishing head so as to realize the high efficiency of the polishing step.

Description

Wafer polishing head

The present invention relates to a wafer polishing head for holding a semiconductor wafer in a polishing process of a semiconductor wafer.

Conventionally, as a chuck mechanism for surface-based polishing that performs polishing based on the polishing surface, which is the surface of a semiconductor wafer, a chuck mechanism having a suction chuck such as a rubber chuck formed of an elastic body is known.

For example, the semiconductor wafer polishing apparatus disclosed in Japanese Patent Laid-Open No. 7-263386 has a pad member for sucking and holding the semiconductor wafer. The cushion member is formed of an elastic body such as silicon rubber or silicon foam. The gasket member made of an elastic body disclosed in this document is fixedly mounted on the lower surface of a holding plate which is provided above the polishing platform. The semiconductor wafer is attached to the cavity where the semiconductor wafer enters in a state of being wetted by pure water. As a result, the semiconductor wafer is fixedly mounted and held in the void portion via the water film.

According to the above-mentioned structure, the semiconductor wafer is sucked and held by the spacer member formed of an elastic body. Therefore, the warpage of the semiconductor wafer is corrected, and the surface of the semiconductor wafer is pressed against the polishing cloth of the polishing table. In this way, polishing is performed not on the back surface of the semiconductor wafer but on the surface thereof.

In addition, for example, Japanese Patent Application Publication No. 2009-107094 discloses a so-called rubber chuck type polishing head in which a workpiece is held by a rubber film. The polishing head is provided with a shoe-shaped rubber film having an O-ring end. According to the structure of this polishing head, by supplying fluid from the pressure adjusting mechanism to the sealed space sealed by the rubber film, the rubber film expands and a load is applied to the back surface of the workpiece.

In addition, as an example of other prior art, the following chuck mechanism is known about a polishing apparatus for a semiconductor wafer. The chuck mechanism is a chuck mechanism of a wafer polishing head that holds and rotates a wafer to be processed. This chuck mechanism has an adsorption chuck such as a rigid body chuck formed of a rigid body.

For example, the chuck mechanism disclosed in Japanese Patent Laid-Open Publication No. 11-309672 has a rigid suction cup formed of a porous ceramic plate that can directly suck a wafer. The chuck mechanism includes a liquid supply nozzle that ejects liquid onto the surface of the chuck where the wafer is adsorbed. According to this chuck mechanism, in a state where the chamber of the head to which the suction cup is mounted is decompressed, the liquid supply nozzle ejects liquid to the suction cup. Then, the wafer is sucked by the sucking surface of the sucker.

Then, after stopping the ejection of the liquid from the liquid supply nozzle, the chuck mechanism is lowered onto the polishing cloth, and the wafer abuts the polishing cloth. With the rotation of the wafer and the rotation of the polishing cloth, the surface of the wafer is polished by the polishing cloth.

As shown in the prior art disclosed in Japanese Patent Laid-Open No. 7-263386 and Japanese Patent Laid-Open No. 2009-107094, according to a rubber chuck type wafer polishing head having a rubber chuck or the like, a suction chuck , It is possible to perform polishing with high flatness and high precision based on the surface of the semiconductor wafer.

However, according to the wafer polishing head for surface reference polishing based on the rubber chuck method of the related art, it is difficult to perform back surface reference polishing with the back surface of the semiconductor wafer as a reference. In the prior art, in order to perform back-side reference polishing, it is necessary to replace the polishing head with a wafer polishing head capable of performing back-side reference polishing and to exchange semiconductor wafers.

As shown in the prior art disclosed in Japanese Patent Application Laid-Open No. 11-309672, according to a wafer polishing head having a rigid chuck formed of a rigid body such as a porous ceramic plate, a highly rigid suction cup can be used to grind a semiconductor wafer Keep the back flat. Therefore, it is possible to perform backside reference polishing with the backside as a reference.

However, according to the wafer polishing head of the rigid chuck method of the prior art having a rigid chuck formed of a rigid body, it is difficult to perform surface reference polishing with the surface of the semiconductor wafer as a reference.

Therefore, according to the prior art, in order to achieve a suitable processing method corresponding to the requirements of the processing object, it is necessary to prepare a rubber chuck type wafer polishing head with a rubber chuck and a rigid chuck type wafer with a rigid chuck. Grind both sides with the head. In this case, the wafer polishing head of the rubber chuck method and the wafer polishing head of the rigid chuck method are replaced and used in accordance with the processing steps. Therefore, the replacement process takes time.

The present invention has been completed in view of the above-mentioned circumstances. An object of the present invention is to provide a wafer polishing head, which can improve the productivity of a wafer polishing apparatus and can achieve an efficient polishing step.

A wafer polishing head according to an aspect of the present invention includes: a chuck mechanism including a rubber chuck formed of an elastic body and a rigid body chuck formed of a rigid body; and a first pressure adjusting mechanism capable of supplying to the vicinity of the rubber chuck Air; and a second pressure adjustment mechanism capable of supplying air to the vicinity of the rigid body chuck, and the wafer polishing head can switch the air supply of the first pressure adjustment mechanism and the second pressure adjustment mechanism Air is supplied, and the processing method is switched.

The wafer polishing head (this wafer polishing head) according to one aspect of the present invention includes a rubber chuck formed of an elastic body and a rigid body chuck formed of a rigid body as a chuck mechanism. Furthermore, this wafer polishing head has a first pressure adjustment mechanism capable of supplying air to the vicinity of the rubber chuck and a second pressure adjustment mechanism capable of supplying air to the vicinity of the rigid body chuck. According to this wafer polishing head, by switching the air supply of the first pressure adjusting mechanism and the air supply of the second pressure adjusting mechanism, the processing method can be switched. As a result, it is possible to switch between the polishing processing of the rubber chuck method and the polishing processing of the rigid chuck method using one of the wafer polishing heads. This eliminates the need to separately provide a wafer polishing head with a rubber chuck and a wafer polishing head with a rigid chuck. Therefore, the productivity of the wafer polishing apparatus can be improved. In addition, there is no need for a step of replacing the wafer polishing head with the rubber chuck and the polishing head with the rigid chuck, so that the efficiency of the polishing step can be improved.

In addition, according to the wafer polishing head of the present invention, it is preferable that the rubber chuck is configured to press the wafer to be processed from its lower surface. Furthermore, it is preferable that the rigid body chuck is configured such that its lower surface can abut on the upper surface of the rubber chuck. As a result, it is possible to use the rubber chuck to press the wafer for polishing processing similarly to a rubber chuck type wafer polishing head having only a rubber chuck in the related art. In addition, by making the rigid chuck abut on the upper surface of the rubber chuck, it is possible to suck and hold the wafer substantially the same as the conventional wafer polishing head of the rigid chuck method having only the rigid chuck.

In addition, according to the wafer polishing head, it is preferable that the first pressure adjusting mechanism can supply air between the upper surface of the rubber chuck and the lower surface of the rigid chuck. Furthermore, it is preferable that the second pressure adjustment mechanism can supply air to the upper surface of the rigid body chuck. Thus, by supplying air between the upper surface of the rubber chuck and the lower surface of the rigid chuck by the first pressure adjusting mechanism, a rubber chuck type chuck mechanism in which the wafer is held by the lower surface of the rubber chuck can be constructed. In addition, by supplying air to the upper surface of the rigid body chuck by the second pressure adjusting mechanism, the lower surface of the rigid body chuck is in contact with the upper surface of the rubber chuck to form a rigid body holding the wafer under the rubber chuck. The chuck mechanism of the chuck method.

In addition, according to the wafer polishing head of the present invention, it is preferable that the rigid body chuck is formed of a porous body. As a result, high-precision air pressure adjustment by the rigid body chuck can be realized. As a result, the upper surface of the rubber chuck can be rigidly supported so that the rubber chuck becomes flat. As a result, the wafer polishing head of the present invention can exhibit an excellent function as a rigid chuck type wafer polishing head.

In addition, according to the wafer polishing head of the present invention, it is preferable to configure a chuck mechanism for surface reference polishing in a state where air is supplied by the first pressure adjusting mechanism. Furthermore, it is preferable to constitute a chuck mechanism for back surface reference grinding in a state where air is supplied from the second pressure adjusting mechanism. This eliminates the need to prepare two wafer polishing heads, namely a wafer polishing head for surface reference polishing and a wafer polishing head for back surface reference polishing. Instead, one wafer polishing head can perform surface reference. Grinding and back reference grinding. As a result, the types of wafer polishing heads included in the wafer polishing apparatus can be reduced. As a result, the productivity of the wafer polishing apparatus can be improved. Furthermore, since there is no need to replace the wafer polishing head, it is possible to increase the efficiency of the polishing process.

In addition, according to the wafer polishing head, it is preferable that the first pressure adjusting mechanism can open the vicinity of the rubber chuck to the atmosphere and can suck air from the vicinity of the rubber chuck. The pressure in the vicinity of the rubber chuck can be adjusted to a positive pressure by supplying air to the vicinity of the rubber chuck by the first pressure adjusting mechanism configured in this way to pressurize it. Furthermore, by opening the vicinity of the rubber chuck to the atmosphere, the pressure in the vicinity of the rubber chuck can be adjusted to atmospheric pressure. Furthermore, the pressure in the vicinity of the rubber chuck is reduced by suction of air, so that the pressure in the vicinity of the rubber chuck can be adjusted to a negative pressure. Thereby, it is possible to switch between the chuck mechanism of the rubber chuck system and the chuck mechanism of the rigid body chuck system with high accuracy.

Hereinafter, the wafer polishing head 1 according to the embodiment of the present invention will be described in detail based on the drawings. FIG. 1 is a diagram showing a schematic configuration of a wafer polishing apparatus equipped with a wafer polishing head 1 according to an embodiment of the present invention.

1, the wafer polishing head 1 is installed in a wafer polishing apparatus. The wafer polishing head 1 is a device that sucks and holds the wafer W in the process of polishing the wafer W. The wafer W is, for example, a semiconductor wafer.

The wafer polishing device is a device that polishes the wafer W. The wafer polishing apparatus includes a freely rotating table 30, a liquid supply nozzle 33, and a wafer polishing head 1.

The worktable 30 is freely rotatably arranged on the platform. The table 30 is rotated by a rotating shaft 32 by being driven by a driving device not shown.

A loading platform is provided on the upper surface of the workbench 30. A polishing cloth 31 for polishing the wafer W is placed on the upper surface of the upper stage. The polishing cloth 31 placed on the upper surface of the upper stage can be vacuum sucked on the upper stage by, for example, a decompression device not shown.

A chamber (not shown) is formed on the lower surface side of the upper stage in the interior of the table 30. By depressurizing the chamber by a decompression device not shown, the polishing cloth 31 placed on the upper surface of the upper stage can be sucked by the upper surface.

For the upper stage, for example, a plate made of porous raw material is used. Examples of porous raw materials include porous alumina, porous ceramics, sintered metals, and other synthetic resins.

The polishing cloth 31 is a cloth material for polishing the wafer W. For the polishing cloth 31, for example, a foamed polyurethane sheet or felt can be used.

The liquid supply nozzle 33 is a nozzle for supplying liquid for polishing to the polishing cloth 31, the wafer W, the rubber chuck 10 (refer to FIG. 2), and the like. As the liquid for polishing sprayed from the liquid supply nozzle 33, for example, purified water, alkaline aqueous solution, and acidic aqueous solution can be cited.

The wafer polishing head 1 is a device that rotates while holding a wafer W as a processing target. The wafer polishing head 1 is driven to rotate by a driving device (not shown) via a rotating shaft 27 while holding the wafer W below it. The wafer W rotates with its upper surface held by the wafer polishing head 1. The lower surface of the wafer W is pressed against the upper surface of the polishing cloth 31 rotating on the table 30 to be polished. Hereinafter, the lower surface of the wafer W serving as the polished surface is appropriately referred to as the surface. On the other hand, the upper surface of the wafer W is referred to as the back surface.

FIG. 2 is a schematic cross-sectional view showing the schematic configuration of the wafer polishing head 1. As shown in FIG. 2, the wafer polishing head 1 includes a rubber chuck 10 and a rigid chuck 11 as a chuck mechanism.

The wafer polishing head 1 has a function as a chuck mechanism of a rubber chuck system, and has a function of a chuck mechanism of a rigid body chuck system. The wafer polishing head 1 can switch between a rubber chuck method and a rigid chuck method.

The rubber chuck 10 is a substantially disc-shaped member formed of an elastic body such as a synthetic rubber material. The vicinity of the outer peripheral portion of the rubber chuck 10 is fixed to a support portion (not shown) provided in the vicinity of the outer peripheral portion of the chuck holding member 12.

The rigid chuck 11 is a substantially disc-shaped member formed of a rigid material such as porous ceramics, porous alumina, sintered metal plate, aluminum, or other synthetic resins. The rigid body chuck 11 is arranged above the rubber chuck 10. The vicinity of the outer peripheral portion of the rigid chuck 11 is held by a support portion (not shown) provided near the outer peripheral portion of the chuck holding member 12. By forming the rigid chuck 11 from a porous body, high-precision air pressure adjustment by the rigid chuck 11 can be realized. Thereby, the upper surface of the rubber chuck 10 can be rigidly supported so that the rubber chuck 10 may become flat. Therefore, the wafer polishing head 1 can exhibit an excellent function as the wafer polishing head 1 of the rigid chuck method.

The wafer polishing head 1 includes a first pressure adjustment mechanism 23. The first pressure adjustment mechanism 23 can supply air to the vicinity of the rubber chuck 10, open the vicinity of the rubber chuck 10 to the atmosphere, and can suck air from the vicinity of the rubber chuck 10. The first pressure adjusting mechanism 23 can supply air to the vicinity of the rubber chuck 10, for example, between the rubber chuck 10 and the rigid body chuck 11. The first pressure adjusting mechanism 23 has an air pipe, an air valve, and the like, which are not shown, and is connected to a vacuum pump, a compressor, and the like, which are not shown. The first pressure adjusting mechanism 23 having such a structure supplies air between the upper surface of the rubber chuck 10 and the lower surface of the rigid chuck 11. In addition, the first pressure adjusting mechanism 23 discharges air from between the upper surface of the rubber chuck 10 and the lower surface of the rigid body chuck 11. Thereby, the first pressure adjusting mechanism 23 adjusts the pressure between the rubber chuck 10 and the rigid chuck 11.

The wafer polishing head 1 includes a second pressure adjustment mechanism 24. The second pressure adjustment mechanism 24 can supply air to the vicinity of the rigid chuck 11. The second pressure adjustment mechanism 24 is provided, for example, to be able to supply air to the upper side (upper surface) of the rigid chuck 11 inside the chuck holding member 12. The second pressure adjustment mechanism 24 is a mechanism for adjusting the pressure of the air above the rigid chuck 11.

The second pressure adjustment mechanism 24 has an unshown air pipe, an air valve, and the like, and is connected to an unshown compressor or the like. The second pressure adjusting mechanism 24 supplies air to the upper surface of the rigid body chuck 11 or discharges air from the upper surface of the rigid body chuck 11. In this way, the second pressure adjustment mechanism 24 adjusts the pressure above the rigid chuck 11.

A chuck base 26 is provided above the chuck holding member 12. The chuck base 26 is a member that supports the chuck holding member 12. In the process of polishing the wafer W (see FIG. 1 ), the chuck base 26 transmits a driving force for rotating the chuck holding member 12. In addition, the chuck base 26 abuts on the upper surface of the chuck holding member 12, and presses the chuck holding member 12 downward so that the lower surface of the rubber chuck 10 contacts the wafer W and presses the wafer W.

A substantially disc-shaped drive ring 28 is provided at the lower part of the chuck base 26. The drive ring 28 is formed of spring steel or the like. The surface of the drive ring 28 is covered by a rubber member. The vicinity of the outer periphery of the drive ring 28 is fixed to the chuck base 26. The vicinity of the inner peripheral portion of the drive ring 28 is slidably connected to the rotating shaft portion of the chuck holding member 12.

A rotating shaft 27 is provided on the upper part of the chuck base 26. The wafer polishing head 1 is rotated by rotational power transmitted via a rotating shaft 27 by a driving device not shown. The rotating shaft 27 is formed with a hollow portion that constitutes a third pressure adjustment mechanism 25 described later.

Above the drive ring 28 in the inside of the chuck base 26, a space as the cavity 22 is formed. The hollow part of the rotating shaft 27 communicates with the cavity 22. The hollow portion of the rotating shaft 27 constitutes a third pressure adjustment mechanism 25 for adjusting the pressure of the air in the chamber 22.

The third pressure adjustment mechanism 25 has an unshown air pipe, an air valve, etc., and is connected to an unshown compressor or the like. The third pressure adjustment mechanism 25 supplies air to the chamber 22 or discharges air from the chamber 22. In this way, the third pressure adjustment mechanism 25 adjusts the pressure of the chamber 22.

Next, referring to FIGS. 1 and 2, the manner in which the wafer polishing head 1 is used for polishing processing will be described in detail.

First, a mode when the wafer polishing head 1 is made to function as a chuck mechanism of a rubber chuck method will be described.

When the wafer polishing head 1 functions as a chuck mechanism of a rubber chuck system, the first pressure adjusting mechanism 23 supplies air between the rubber chuck 10 and the rigid chuck 11 in the polishing step. Thereby, the rubber chuck 10 and the rigid body chuck 11 are pressurized, and the pressure of this part is adjusted to a positive pressure. On the other hand, the upper part of the rigid body chuck 11 is opened to the atmosphere by the second pressure adjusting mechanism 24. As a result, the pressure above the rigid chuck 11 is adjusted to atmospheric pressure. Furthermore, the chamber 22 is pressurized by the air supply of the third pressure adjustment mechanism 25, and the pressure of the chamber 22 is adjusted to a positive pressure.

In this way, the pressure between the rubber chuck 10 and the rigid body chuck 11 is adjusted to a positive pressure, and the pressure above the rigid body chuck 11 is adjusted to the atmospheric pressure. Thus, the pressing of the rubber chuck 10 by the rigid chuck 11 is restricted. Thereby, a rubber chuck type chuck mechanism in which the wafer W is held by the lower surface of the rubber chuck 10 can be constructed.

If the chuck base 26 is driven by the drive unit to rotate and is pushed downward from above, the rotational driving force and pushing force are transmitted to the chuck through the chamber 22 and the drive ring 28 whose pressure is adjusted to a positive pressure. Hold the upper part of the component 12. Then, the rotational driving force and the pushing force are transmitted from the chuck holding member 12 to the rubber chuck 10. Thereby, it is possible to perform polishing processing including holding the wafer W on the lower surface of the rubber chuck 10 and pressing the surface of the wafer W on the upper surface of the polishing cloth 31 to rotate the surface of the wafer W.

Here, the rubber chuck 10 is formed of an elastic body. In addition, it is difficult to restrict the elastic deformation of the rubber chuck 10 by the pressing of the rigid chuck 11. Therefore, the lower surface of the rubber chuck 10 can be deformed to fit the shape of the upper surface, that is, the back surface of the wafer W. In this way, a chuck mechanism capable of performing surface reference polishing with the lower surface, that is, the surface of the wafer W, as a reference is constructed. That is, the surface reference polishing is performed in which the surface of the wafer W is flattened with high accuracy using the surface of the wafer W as a reference. Thereby, a wafer W having excellent flatness can be obtained. In this way, in a state where air is supplied by the first pressure adjusting mechanism 23, a chuck mechanism for surface reference polishing is constructed.

Next, a method of making the wafer polishing head 1 function as a chuck mechanism of a rigid chuck method will be described in detail.

When the wafer polishing head 1 functions as a chuck mechanism of a rigid chuck system, the first pressure adjusting mechanism 23 opens the space between the rubber chuck 10 and the rigid chuck 11 to the atmosphere in the polishing step. As a result, the pressure of this part is adjusted to atmospheric pressure. On the other hand, the upper surface of the rigid body chuck 11 is pressurized by the second pressure adjusting mechanism 24. As a result, the pressure above the rigid chuck 11 is adjusted to a positive pressure. Furthermore, the chamber 22 is pressurized by the third pressure adjusting mechanism 25, and the pressure of the chamber 22 is adjusted to a positive pressure.

In this way, the pressure between the rubber chuck 10 and the rigid chuck 11 is adjusted to atmospheric pressure, and the pressure above the rigid chuck 11 is adjusted to a positive pressure. Thereby, the lower surface of the rigid body chuck 11 and the upper surface of the rubber chuck 10 abut against each other. That is, there is substantially no gap between the upper surface of the rubber chuck 10 and the lower surface of the rigid chuck 11. In other words, the rubber chuck 10 is in a state of being held by the rigid rigid body chuck 11 that is in contact with the upper surface of the rubber chuck 10 and is formed of a rigid body.

If the chuck base 26 is driven by the drive unit to rotate and is pushed downward from above, the rotational driving force and pushing force of the chamber 22 and the drive ring 28 whose pressure is adjusted to a positive pressure are transmitted to the card The upper part of the disc holding member 12. Then, the rotational driving force and the pushing force are transmitted from the chuck holding member 12 to the rigid body chuck 11 and the rubber chuck 10. Thereby, it is possible to perform polishing processing including holding the wafer W on the lower surface of the rubber chuck 10 and pressing the surface of the wafer W on the upper surface of the polishing cloth 31 to rotate the surface of the wafer W.

Here, the upper surface of the rubber chuck 10 is held in contact with the flat lower surface of the rigid body chuck 11 formed of a rigid body. Therefore, the lower surface of the rubber chuck 10 can press the upper surface or back surface of the wafer W and hold the upper surface or back surface of the wafer W flat. In this way, a chuck mechanism capable of performing backside reference polishing with the backside of the wafer W as a reference is constructed. As a result, the back surface reference polishing in which the back surface of the wafer W is used as a reference and the back surface is held flat is performed. Thereby, a wafer W having excellent surface roughness can be obtained. In this way, in a state where air is supplied by the second pressure adjusting mechanism 24, a chuck mechanism for back surface reference polishing is constituted.

Next, the state of the wafer polishing head 1 in the wafer transport process will be described in detail.

In the wafer transport process, the pressure between the rubber chuck 10 and the rigid chuck 11 is reduced by the air suction of the first pressure adjusting mechanism 23, and the pressure of this portion is adjusted to a negative pressure. On the other hand, the upper surface of the rigid body chuck 11 is pressurized by the second pressure adjusting mechanism 24, and the pressure on the upper surface of the rigid body chuck 11 is adjusted to a positive pressure. Furthermore, the chamber 22 is opened to the atmosphere by the third pressure adjustment mechanism 25, and the pressure of the chamber 22 is adjusted to the atmospheric pressure.

In this way, the pressure between the rubber chuck 10 and the rigid chuck 11 is adjusted to a negative pressure, and the pressure on the upper surface of the rigid chuck 11 is adjusted to a positive pressure. Thereby, the lower surface of the rigid body chuck 11 is held by the upper surface of the rubber chuck 10 in a state of being in contact with the upper surface of the rubber chuck 10. That is, there is substantially no gap between the upper surface of the rubber chuck 10 and the lower surface of the rigid chuck 11. In other words, the rubber chuck 10 is held by the rigid body chuck 11 that is in contact with the upper surface thereof and is formed of a rigid body. Thereby, the rubber chuck 10 can suck the wafer W in a flat state.

In the vicinity of the upper peripheral edge of the rotating shaft portion of the chuck holding member 12 (not shown), a support portion (not shown) for supporting the chuck holding member 12 in the conveyance process is formed. The support portion has, for example, a substantially annular shape protruding in the radial direction. In addition, a support member (not shown) is provided inside the chuck base 26. The support member abuts on the support portion of the chuck holding member 12 and supports the chuck holding member 12. The supporting member has, for example, a substantially annular shape.

In the transport process, if the chuck base 26 is lifted by a driving device not shown, the support member of the chuck base 26 abuts against the support portion of the chuck holding member 12, and the chuck holding member 12 is lifted . As a result, the rubber chuck 10 rises in a state where the wafer W is adsorbed on the lower surface. The wafer W is separated from the polishing cloth 31 in a state of being sucked by the rubber chuck 10 and transported.

As described above, the rigid body chuck 11 formed of a rigid body abuts on the upper surface of the rubber chuck 10 during transportation. Thereby, the deformation of the rubber chuck 10 is suppressed, and the rubber chuck 10 can suck and transport the thin wafer W in a flat state.

As described above, the wafer polishing head 1 of the present embodiment includes the rubber chuck 10 formed of an elastic body and the rigid rigid chuck 11 formed of a rigid body as a chuck mechanism. Furthermore, the wafer polishing head 1 has a first pressure adjusting mechanism 23 capable of supplying air between the upper surface of the rubber chuck 10 and the lower surface of the rigid body chuck 11, and a second pressure capable of supplying air to the upper surface of the rigid body chuck 11. Adjustment mechanism 24. The wafer polishing head 1 is configured to be able to switch the processing method by switching the air supply of the first pressure adjusting mechanism 23 and the air supply of the second pressure adjusting mechanism 24.

With the above structure, the wafer polishing head 1 can have both the function of a chuck mechanism based on the rubber chuck 10 as a rubber chuck method and the function of a chuck mechanism based on the rigid body chuck 11 as a rigid chuck method. These two functions can be adjusted (switched).

As a result, the wafer polishing apparatus is provided with the wafer polishing head 1 so that it is not necessary to separately provide a wafer polishing head dedicated to the rubber chuck method and a wafer polishing head dedicated to the rigid chuck method. That is, the wafer polishing apparatus may include one wafer polishing head 1. Therefore, the types of wafer polishing heads included in the wafer polishing apparatus can be reduced. As a result, the productivity of the wafer polishing apparatus can be improved. In addition, there is no need to replace the wafer polishing head dedicated for the rubber chuck method and the wafer polishing head dedicated for the rigid chuck method, so that the efficiency of the polishing step can be improved.

For example, when constructing a chuck mechanism for surface reference polishing, instead of replacing the wafer polishing head 1, the pressure between the upper surface of the rubber chuck 10 and the lower surface of the rigid chuck 11 is adjusted to a positive pressure, and the The pressure on the upper surface of the rigid chuck 11 is adjusted to atmospheric pressure. On the other hand, when constructing a chuck mechanism for back surface reference grinding, the pressure between the upper surface of the rubber chuck 10 and the lower surface of the rigid chuck 11 is adjusted to atmospheric pressure, and the pressure on the upper surface of the rigid chuck 11 is adjusted to Positive pressure. In addition, in the wafer transport process, the pressure between the upper surface of the rubber chuck 10 and the lower surface of the rigid chuck 11 is adjusted to a negative pressure, and the pressure of the upper surface of the rigid chuck 11 is adjusted to a positive pressure. As a result, it is not necessary to separately prepare a wafer polishing head for surface reference polishing, a wafer polishing head for back reference polishing, and a wafer polishing head for wafer transport, but one wafer polishing head 1 can be used. Perform surface reference grinding, back reference grinding and wafer handling.

In addition, the mode of the present invention is not limited to the above-mentioned embodiment. In addition to the above-mentioned embodiments, the modes of the present invention can be modified in various ways without departing from the scope of the concept of the present invention.

In addition, in this specification, the expressions "B formed by A" and "B formed by A" mean "B including A as a main component" and include "B which substantially only includes A" and " "B containing A" and "B containing A and other ingredients".

1: Wafer polishing head 10: Rubber chuck 11: Rigid body chuck 12: Chuck holding parts 22: Chamber 23: The first pressure adjustment mechanism 24: The second pressure adjustment mechanism 25: The third pressure adjustment mechanism 26: Chuck base 27: Rotation axis 28: drive ring 30: workbench 31: Abrasive cloth 32: Rotation axis 33: Liquid supply nozzle W: Wafer

FIG. 1 is a diagram showing a schematic configuration of a wafer polishing apparatus equipped with a wafer polishing head according to an embodiment of the present invention. 2 is a schematic cross-sectional view showing the schematic configuration of a wafer polishing head according to an embodiment of the present invention.

1: Wafer polishing head

10: Rubber chuck

11: Rigid body chuck

12: Chuck holding parts

22: Chamber

23: The first pressure adjustment mechanism

24: The second pressure adjustment mechanism

25: The third pressure adjustment mechanism

26: Chuck base

27: Rotation axis

28: drive ring

Claims (6)

A wafer polishing head, comprising: a chuck mechanism having a rubber chuck formed by an elastic body and a rigid body chuck formed by a rigid body; A first pressure adjusting mechanism capable of supplying air to the vicinity of the rubber chuck; and A second pressure adjustment mechanism capable of supplying air to the vicinity of the rigid body chuck, The wafer polishing head can switch the processing method by switching the air supply of the first pressure adjusting mechanism and the air supply of the second pressure adjusting mechanism. The wafer polishing head according to claim 1, wherein the rubber chuck is configured to press a wafer to be processed from its lower surface, and The rigid body chuck is configured such that its lower surface can abut against the upper surface of the rubber chuck. The wafer polishing head according to claim 2, wherein the first pressure adjusting mechanism can supply air between the upper surface of the rubber chuck and the lower surface of the rigid body chuck, The second pressure adjustment mechanism can supply air to the upper surface of the rigid chuck. The wafer polishing head according to any one of claims 1 to 3, wherein the rigid body chuck is formed of a porous body. The wafer polishing head according to any one of claims 1 to 4, wherein the chuck mechanism for surface reference polishing is configured in a state where air is supplied by the first pressure adjusting mechanism, In a state where air is supplied by the second pressure adjustment mechanism, the chuck mechanism for back surface reference grinding is constituted. The wafer polishing head according to any one of claims 1 to 5, wherein the first pressure adjustment mechanism is capable of opening the vicinity of the rubber chuck to the atmosphere, and capable of opening the vicinity of the rubber chuck to the atmosphere. Attract air nearby.

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