CN1748293A - Substrate holding device and polishing device - Google Patents

Abstract

The present invention relates to a substrate holding apparatus for holding a substrate (W), such as a semiconductor wafer, in a polishing apparatus for polishing the substrate to a flat finish. The substrate holding apparatus includes a vertically movable member (6) and a resilient member (7) for defining a chamber (22). The elastic member (7) includes a contact portion (8) which contacts the substrate (W) and a peripheral wall (9) which extends upward from the contact portion (8) and is connected to the vertically movable member (6). The peripheral wall (9) has a vertically extendable and retractable portion (40).

Description

Substrate holding device and polishing device

                      

The invention relates to a substrate holding device for holding a substrate to be polished and pressing the substrate against a polishing surface, in particular to a substrate holding device for polishing a substrate to a flat smooth surface. Substrate holders for substrates, such as semiconductor wafers. The invention also relates to a polishing device having such a substrate holder.

Background technique

In recent years, semiconductor devices have become more integrated, and the structure of semiconductor elements has also become more complicated. In addition, the number of layers used in the multilayer interconnection of the logic system is also increased. Therefore, the irregularity of the surface of the semiconductor device increases, so that the step height of the surface of the semiconductor device tends to be larger. This is because, in the manufacturing process of a semiconductor device, a thin film is formed on the semiconductor device, and then the semiconductor device is subjected to micromachining processing, such as forming patterns or holes, and these processes are repeated many times to form a thin film on the semiconductor device. Follow-up film.

When the irregularities of the surface of the semiconductor device increase, the following problems arise. When forming a thin film on a semiconductor device, the thickness of the thin film formed at a portion having a step is relatively small. An open circuit due to disconnection of an interconnection or a short circuit due to insufficient insulation between interconnection layers. Therefore, a good product cannot be obtained, and the yield will also decrease. Furthermore, even if the semiconductor device works normally initially, the reliability of the semiconductor device decreases after long-term use. When exposure is performed in a lithographic process, if the radiation surface has irregularities, the lens system in the exposure system cannot focus locally. Therefore, if the irregularities of the surface of the semiconductor device increase, there arises a problem that it is difficult to form a fine pattern on the semiconductor device.

Therefore, planarizing the surface of semiconductor devices is becoming more and more important in the manufacturing process of semiconductor devices. One of the most important planarization techniques is CMP (Chemical Mechanical Polishing). In chemical mechanical polishing, a polishing apparatus is used to slide a substrate such as a semiconductor wafer with a polishing surface while supplying a polishing liquid containing abrasive grains such as silica (SiO ₂ ) therein onto a polishing surface such as a polishing pad. contact, thereby polishing the substrate.

Such polishing devices include a polishing table having a polishing surface constituted by a polishing pad and a substrate holding device called a top ring or carrier head for holding a semiconductor wafer. When polishing a semiconductor wafer with such a polishing apparatus, the semiconductor wafer is held and pressed against a polishing table by a substrate holding means at a predetermined pressure. At this time, the polishing table and the substrate holding device are moved relative to each other, so that the semiconductor wafer comes into sliding contact with the polishing surface, thereby polishing the surface of the semiconductor wafer to a flat mirror finish level.

In this polishing apparatus, if the relative pressing force between the semiconductor wafer to be polished and the polishing surface of the polishing pad is not uniform on the entire surface of the semiconductor wafer, some Depending on the pressing force on the semiconductor wafer, the semiconductor wafer may be underpolished or may be overpolished. Therefore, people try to form the surface of the substrate holding device with an elastic film made of elastic material, such as rubber, to hold the semiconductor wafer, and apply fluid pressure, such as air pressure, to the back of the elastic film so that the pressure applied to the semiconductor wafer The pressure is evenly distributed over the entire surface of the semiconductor wafer.

In addition, the elasticity of the polishing pad makes the pressure applied to the peripheral portion of the semiconductor wafer to be polished non-uniform, whereby only the peripheral portion of the semiconductor wafer may be over-polished, which is called "corner rounding". In order to avoid such corner rounding, a substrate holding device is used in which the semiconductor wafer is held at its peripheral portion by a guide ring or snap ring, and the annular portion on the polishing surface corresponding to the peripheral portion of the semiconductor wafer is held by the guide ring. or snap ring.

Next, a conventional substrate holding device will be described with reference to Figs. 29A and 29B. 29A and 29B show a partial cross-sectional view of a conventional substrate holding device.

As shown in FIG. 29A , the substrate holding device has a top ring body 2 , a chuck 6 located in the top ring body 2 , and an elastic film 80 attached to the chuck 6 . The elastic film 80 is located on the outer peripheral portion of the chuck 6 and is in contact with the peripheral edge of the semiconductor wafer W. As shown in FIG. An annular snap ring 3 is held at the lower end of the top ring body 2 and presses the polishing surface near the peripheral edge of the semiconductor wafer W. As shown in FIG.

The chuck 6 is installed on the top ring body 2 through the elastic pressing piece 13 . The chuck 6 and the elastic membrane 80 move vertically relative to the top ring body 2 and the snap ring 3 within a certain range under the action of fluid pressure. A substrate holder having such a structure is called a so-called floating substrate holder. A pressure chamber 130 is defined by the elastic membrane 80, the lower surface of the chuck 6, and the upper surface of the semiconductor wafer W. As shown in FIG. A pressurized fluid is introduced into the pressure chamber 130, thereby lifting the chuck 6 and simultaneously pressing the semiconductor wafer W against the polishing surface. In this state, the polishing liquid is supplied onto the polishing surface, and the top ring (substrate holder) and the polishing surface are rotated independently of each other, thereby polishing the lower surface of the semiconductor wafer W to a flat smooth surface.

After the polishing process is finished, the semiconductor wafer W is attracted by vacuum and held by the top ring. The top ring holds the semiconductor wafer W to move to a transfer position, and then ejects a liquid (such as pressurized fluid or a mixture of nitrogen and pure water) from the lower part of the chuck 6 to release the semiconductor wafer W.

However, in the above-mentioned conventional floating substrate holding device, when the chuck 6 moves upward to press the semiconductor wafer W, the elastic film 80 kept in contact with the outer peripheral edge of the semiconductor wafer W is lifted by the chuck 6, thereby causing The outer peripheral edge of the elastic film 80 is out of contact with the semiconductor wafer W. As shown in FIG. Therefore, the pressing force applied on the semiconductor wafer W is locally changed at the outer peripheral edge of the semiconductor wafer W. As shown in FIG. Then, the polishing rate decreases at the outer peripheral edge of the semiconductor wafer W, and the polishing rate increases at a region located radially inward of the outer peripheral edge of the semiconductor wafer W.

This problem is exacerbated as the hardness of the elastic membrane increases. Therefore, attempts have been made to use an elastic film with a low hardness so that the contact area between the elastic film and the semiconductor wafer remains unchanged. However, in the floating substrate holding device, the semiconductor wafer W is polished while the snap ring 3 is kept in sliding contact with the polishing surface. Therefore, the snap ring 3 tends to be worn over time, resulting in a decrease in the distance between the semiconductor wafer W and the chuck 6 (see FIG. 29B ). Then, the pressure applied to the outer circumferential edge of the semiconductor wafer W changes, whereby the polishing rate changes at the outer circumferential edge of the semiconductor wafer W, resulting in a change in the polishing profile. Furthermore, due to this drawback, a worn snap ring has to be replaced at an initial stage, so that the snap ring has a very short service life.

In addition to the above problems, conventional substrate holding devices have another problem: when the polishing process is about to start, pressurized fluid is fed into the pressure chamber, and the elastic membrane and the semiconductor wafer may not be kept in sufficiently close contact with each other. Therefore, pressurized fluid tends to leak from the gap between the elastic membrane and the semiconductor wafer.

Furthermore, in the step of releasing the semiconductor wafer from the top ring, there occurs a problem that if a film of nitride or the like is formed on the back surface (upper surface) of the semiconductor wafer, the elastic film and the semiconductor wafer adhere to each other. Therefore, when releasing the semiconductor wafer, the elastic membrane may not be able to come out of contact with the semiconductor wafer. In this state, if the pressurized fluid is continuously sprayed on the semiconductor wafer, the elastic film is stretched while maintaining contact with the semiconductor wafer. As a result, the semiconductor wafers are deformed, or in worst case cracked, due to fluid pressure.

In addition, another problem arises in the conventional substrate holder: the pressure chamber constituted by the elastic film is deformed by the fluid pressure. Thus, when pressurized fluid is introduced into the pressure chamber, the elastic membrane is partially out of contact with the semiconductor wafer. Thus, the pressing force applied to the semiconductor wafer is locally lowered, whereby a uniform polishing rate cannot be obtained over the entire polished surface of the semiconductor wafer.

This problem is exacerbated as the hardness of the elastic membrane increases. Therefore, as described above, attempts have been made to use an elastic film with a low hardness so that the contact area between the elastic film and the semiconductor wafer remains unchanged. However, due to the low mechanical strength of the elastic film with low hardness, the elastic film tends to be cracked and needs to be replaced frequently.

Contents of the invention

The present invention is made in view of the above disadvantages. According to the present invention, there is provided a substrate holding device for applying a pressing force to a substrate by supplying a pressurized fluid into a space defined by an elastic membrane. The substrate holding device is configured to stably handle the substrate in all processes including the substrate polishing process and the substrate releasing process. Specifically, the first object of the present invention is to provide a substrate holding device and a polishing apparatus having the substrate holding device, which can apply a uniform pressing force to the entire surface of the substrate, In order to obtain a uniform polishing profile over the entire surface of the substrate. A second object of the present invention is to provide a substrate holding device capable of quickly releasing a substrate and a polishing apparatus having such a substrate holding device. A third object of the present invention is to provide a substrate holding device capable of obtaining a uniform polishing rate over the entire polishing surface of a substrate, and a polishing device having such a substrate holding device.

To achieve the above object, according to one aspect of the present invention, a substrate holding device for holding and pressing a substrate to be polished against a polishing surface is provided, the substrate holding device includes: a vertically movable part; an elastic member connected to the vertically movable member for defining a chamber; the elastic member includes a contact portion in contact with the substrate and a contact portion extending upwardly from the contact portion and in contact with the movable The peripheral wall connected with the vertically movable part has a telescopic part that can vertically expand and contract.

In a preferred aspect of the present invention, the peripheral wall includes an outer peripheral wall and an inner peripheral wall located radially inward of the outer peripheral wall; at least one of the outer peripheral wall and the inner peripheral wall has the stretchable portion; and the contact A portion is divided at a location between the outer peripheral wall and the inner peripheral wall.

Since the present invention has the above-mentioned structure, when the vertically movable member (chuck) moves upward, since the stretchable portion is vertically stretched, the contact portion kept in contact with the substrate can maintain its original shape. Therefore, the contact area between the elastic member and the substrate can remain constant, whereby a uniform pressing force can be obtained over the entire surface of the substrate.

Even if the snap ring is worn causing the distance between the vertically movable member and the substrate to change, the telescoping portion can contract to follow the change in distance. Therefore, the contact portion that remains in contact with the substrate can maintain its original shape. In this way, the substrate can be pressed with uniform pressure over the entire surface from the center of the substrate to its peripheral edge, whereby a uniform polishing rate, ie polishing profile, can be obtained over the entire surface of the substrate. Furthermore, since the telescoping portion shrinks according to the wear of the snap ring, the worn snap ring can still be used without having to be replaced.

In a preferred aspect of the invention, the peripheral wall has a folded portion to form said telescoping portion.

In a preferred aspect of the invention, said folded portion has a substantially arcuate cross-section.

With this structure, the stretchable portion can be smoothly extended downward.

In a preferred aspect of the invention, the stretchable portion is made of a softer material than the contact portion.

In a preferred aspect of the present invention, a predetermined portion of the peripheral wall is thinner than the contact portion to constitute the stretchable portion.

In a preferred aspect of the present invention, the peripheral wall has a portion made of a harder material than the contact portion and located below the telescopic portion.

In a preferred aspect of the present invention, the peripheral wall has a portion thicker than the contact portion and located below the telescopic portion.

In a preferred aspect of the present invention, a hard member harder than the elastic member is embedded in the peripheral wall, and the hard member is located under the telescopic portion.

In a preferred aspect of the present invention, a hard member harder than the elastic member is fixed on the peripheral wall, and the hard member is located under the telescopic portion.

In a preferred aspect of the invention, the peripheral wall has a portion surface-coated with a material harder than the elastic member, and the portion is located below the stretchable portion.

Since the present invention has the above structure, the strength of the peripheral wall can be enhanced, so that the elastic member can be prevented from being twisted when the substrate is polished.

According to another aspect of the present invention, there is provided a substrate holding device for holding and pressing a substrate to be polished against a polishing surface, the substrate holding device comprising: a vertically movable member; The vertically movable member is connected to define an elastic member of a chamber; the elastic member includes a contact portion contacting the substrate and a peripheral wall extending upward from the contact portion and connected to the vertically movable member , wherein the peripheral wall includes an outer peripheral wall and an inner peripheral wall located radially inside of the outer peripheral wall, and the contact portion is separated at a position between the outer peripheral wall and the inner peripheral wall.

In a preferred aspect of the present invention, a pressing member is in contact with the upper surface of the contact portion, thereby pressing the contact portion against the substrate.

Since the present invention has the above structure, the pressing member can bring the lower surface of the contact portion into close contact with the upper surface of the substrate. Therefore, leakage of the pressurized fluid from the gap between the contact portion and the substrate can be prevented.

In a preferred aspect of the present invention, the pressing member has a plurality of grooves formed on its lower surface and extending radially.

In a preferred aspect of the present invention, the pressing member has a fluid supply port formed on its lower surface for supplying fluid to the upper surface of the contact portion.

Since the present invention has the above structure, the pressurized fluid can be quickly supplied to the upper surface of the contact portion through the groove or the fluid supply port. Thus, the pressurized fluid can press the contact portion against the substrate while the contact portion is pressed against the substrate by the pressing member.

In a preferred aspect of the present invention, the contact portion has a thick portion formed on an upper surface thereof and extending in a circumferential direction of the contact portion.

In a preferred aspect of the present invention, the thick portion has a substantially triangular or arc-shaped cross-section.

In a preferred aspect of the invention, a reinforcing member is embedded in the contact portion.

Since the present invention has the above structure, since the strength of the contact portion is enhanced, the contact portion can be prevented from being twisted in the circumferential direction when the pressing member presses the contact portion against the substrate. Therefore, the contact portion and the substrate can be kept in close contact with each other, thereby preventing pressurized fluid from leaking.

In a preferred aspect of the present invention, the contact portion has a plurality of dimples and protrusions formed on an upper surface thereof.

Since the present invention has the above structure, the adhesion of the contact portion to the vertically movable member is weakened. Therefore, when the vertically movable member moves upward, the contact portion of the elastic member can be prevented from being lifted by the vertically movable member.

According to another aspect of the present invention, there is provided a polishing apparatus including: a substrate holding device; and a polishing table having a polishing surface.

According to another aspect of the present invention, there is provided a method for polishing a substrate, comprising: holding the substrate by the above-mentioned substrate holding device; placing the substrate on the polishing surface of the polishing table; moving the vertically movable member downward to Pressing the contact portion against the substrate; supplying a pressurized fluid into the chamber while pressing the contact portion against the substrate; and bringing the substrate into sliding contact with the polishing surface to polish the substrate.

According to another aspect of the present invention, there is provided a substrate holding device for holding and pressing a substrate to be polished against a polishing surface, the substrate holding device comprising: a vertically movable member; and a A resilient member of a chamber; said resilient member has a contact portion in contact with said substrate, and the contact portion has a detachment promoting portion for facilitating the detachment of the contact portion from the substrate.

In a preferred aspect of the present invention, the detachment promoting portion includes a notch formed on a peripheral edge of the contact portion.

In a preferred aspect of the invention, the contact portion has a region made of a material which has lower adhesion to the substrate than to the elastic member.

In a preferred aspect of the present invention, one surface of the contact portion has a plurality of dimples and protrusions.

In a preferred aspect of the present invention, the elastic member includes a plurality of contact portions, and the detachment promoting portion includes an interconnecting portion for interconnecting one of the plurality of contact portions with another.

In a preferred aspect of the present invention, the detachment promoting portion includes an upwardly concave groove formed on the contact portion, and when the pressurized fluid is input into the chamber, the groove comes into close contact with the substrate.

Since the present invention has the above structure, when the fluid is sprayed toward the substrate, the detachment-promoting portion starts to be removed from the substrate, so that the contact portion is detached from the substrate smoothly. Accordingly, the substrate can be transferred to a substrate lifting device, such as a pusher, without being damaged by fluid pressure. Furthermore, the substrate can be smoothly released from the elastic member regardless of the kind of the substrate, particularly the kind of film formed on the backside (upper surface) of the substrate.

According to another aspect of the present invention, there is provided a polishing apparatus including: a substrate holding device; and a polishing table having a polishing surface.

According to another aspect of the present invention, there is provided a substrate holding device for holding and pressing a substrate to be polished against a polishing surface, the substrate holding device comprising: a movable member movable perpendicular to the polishing surface and an elastic membrane connected to the movable member for defining a plurality of chambers; the elastic membrane includes a contact portion contacting the substrate and a plurality of peripheral walls for connecting the contact portion and the movable member , each of the plurality of peripheral walls has a stretchable portion that can expand and contract perpendicularly to the polishing surface.

Since the present invention has the above structure, when the fluid is fed into the above chamber, since the stretchable portion extends perpendicularly to the polishing surface, the contact portion of the elastic member can maintain the original shape. Therefore, the contact area between the elastic film (contact portion) and the substrate can be kept constant, whereby a uniform polishing rate can be obtained over the entire polishing surface of the substrate. In addition, since the elastic film and the substrate are kept in good contact with each other through the stretchable portion, an elastic film of high hardness can be used. Therefore, the durability of the elastic film can be improved. In this case, the high-hardness elastic film can maintain the contact area between the substrate and the elastic film (contact portion) as compared with the low-hardness elastic film. Thus, a stable polishing rate can be obtained.

In a preferred aspect of the invention, the elastic membrane has a unitary structure.

Since the present invention has the above structure, fluid can be prevented from leaking out of the chamber. In addition, the substrate can be easily detached from the contact portion after polishing of the substrate is completed. If the elastic film is divided into a plurality of separate parts, some of these separate parts may adhere to the substrate, thereby preventing smooth detachment of the substrate. According to the present invention, the integrally formed elastic film allows smooth detachment of the substrate from the contact portion.

In a preferred aspect of the present invention, the contact portion has an inclined portion on an outer edge thereof inclined upward.

In a preferred aspect of the present invention, the inclined portion has a curved cross-section.

In a preferred aspect of the present invention, the inclined portion has a straight cross-section.

Since the present invention has the above structure, the peripheral edge of the substrate and the elastic film are kept out of contact with each other. Therefore, no pressing force is exerted on the peripheral edge of the substrate, whereby the peripheral edge of the substrate can be prevented from being over-polished.

In a preferred aspect of the invention, the inclined portion is thinner than the contact portion.

Since the present invention has the above structure, the inclined portion is easily deformed under fluid pressure. Thus, the inclined portion can come into contact with the circumferential edge of the substrate under a desired pressing force. In this way, the polishing rate at the circumferential edge of the substrate can be independently controlled.

According to another aspect of the present invention, there is provided a polishing apparatus including: the substrate holding device; and a polishing table having a polishing surface.

Description of drawings

1 is a cross-sectional view of the overall structure of a polishing apparatus having a substrate holding device according to a first embodiment of the present invention;

2 is a vertical cross-sectional view of a top ring installed in the substrate holding device according to the first embodiment of the present invention;

3A-3C are enlarged cross-sectional views of the middle airbag shown in FIG. 2;

4A is a cross-sectional view of the entire structure of the edge film in the first embodiment of the present invention;

4B and 4C are partial cross-sectional views of the substrate holding device shown in FIG. 2;

5A and 5B are partial cross-sectional views of a substrate holding device according to a second embodiment of the present invention;

6A is a partial cross-sectional view of a substrate holding device according to a third embodiment of the present invention;

6B is a partial cross-sectional view of another structure of an edge film in a third embodiment of the present invention;

7 is a partial cross-sectional view of a substrate holding device according to a fourth embodiment of the present invention;

8A is a cross-sectional view of an edge film according to a fifth embodiment of the present invention;

8B is a cross-sectional view of another structure of an edge film in a fifth embodiment of the present invention;

9A is a cross-sectional view of an edge film according to a sixth embodiment of the present invention;

9B is a reference diagram illustrating stretchability of an edge film according to a sixth embodiment of the present invention;

10A is a cross-sectional view of an edge film according to a seventh embodiment of the present invention;

10B-10E are respectively cross-sectional views of another structure of the edge film in the seventh embodiment of the present invention;

11A and 11B are partial cross-sectional views of a substrate holding device according to an eighth embodiment of the present invention;

12A is a cross-sectional view of a part of a substrate holding device according to a tenth embodiment of the present invention;

Fig. 12B is a view of a part of the substrate holding device viewed along the direction indicated by arrow A in Fig. 12A;

Figure 13 is a view of the interlayer observed along the direction indicated by arrow B in Figure 12A;

14 is a perspective view of an air bag incorporated in a substrate holding device according to a tenth embodiment of the present invention;

15 is a rear view of an elastic member incorporated in a substrate holding device according to an eleventh embodiment of the present invention;

16 is a rear view of a first example of an elastic member incorporated in a substrate holding device according to a twelfth embodiment of the present invention;

17 is a rear view of a second example of an elastic member incorporated in a substrate holding device according to a twelfth embodiment of the present invention;

18 is a rear view of a third example of an elastic member incorporated in a substrate holding device according to a twelfth embodiment of the present invention;

19 is a rear view of a fourth example of an elastic member incorporated in a substrate holding device according to a twelfth embodiment of the present invention;

20 is a cross-sectional view of the overall structure of a polishing apparatus having a substrate holding device according to a thirteenth embodiment of the present invention;

21 is a vertical cross-sectional view of a top ring in a thirteenth embodiment according to the present invention;

Figure 22A is a view of a portion of a top ring according to a thirteenth embodiment of the present invention;

Figure 22B shows the state where fluid is input into the pressure chamber;

23A is a view of a portion of a top ring according to a fourteenth embodiment of the present invention;

Figure 23B shows the state where fluid is input into the pressure chamber;

Figure 24A is a view of a portion of a top ring according to a fifteenth embodiment of the present invention;

Figure 24B shows the state where fluid is input into the pressure chamber;

Figure 25A is a view of a portion of a top ring according to a sixteenth embodiment of the present invention;

Figure 25B shows the state where fluid is input into the pressure chamber;

26A is a view of a part of a substrate holding device according to a seventeenth embodiment of the present invention;

Figure 26B shows the state where fluid is input into the pressure chamber;

27A is an enlarged cross-sectional view of a portion of a first example of a top ring according to an eighteenth embodiment of the present invention;

27B is an enlarged cross-sectional view of a portion of a second example of a top ring according to an eighteenth embodiment of the present invention;

27C is an enlarged cross-sectional view of a portion of a third example of a top ring according to an eighteenth embodiment of the present invention;

28A is an enlarged cross-sectional view of a portion of a first example of a top ring according to a nineteenth embodiment of the present invention;

28B is an enlarged cross-sectional view of a portion of a second example of a top ring according to a nineteenth embodiment of the present invention;

28C is an enlarged cross-sectional view of a portion of a third example of a top ring according to a nineteenth embodiment of the present invention;

29A and 29B are partial cross-sectional views of a conventional substrate holding device.

Detailed ways

A substrate holding device and a polishing device according to a first embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

1 is a cross-sectional view of the overall structure of a polishing apparatus having a substrate holding device according to a first embodiment of the present invention. The substrate holder is used to hold a substrate to be polished, such as a semiconductor wafer, and to press the substrate against a polishing surface of a polishing table. As shown in FIG. 1, under the top ring 1 constituting the substrate holding device according to the present invention, there is a polishing table 100 having a polishing pad 101 attached to its upper surface. There is a polishing liquid supply nozzle 102 above the polishing table 100 , and the polishing liquid Q is applied from the polishing liquid supply nozzle 102 to the polishing surface 101 a of the polishing pad 101 placed on the polishing table 100 .

There are a variety of polishing pads available on the market. For example, there are SUBA800, IC-1000, and IC-1000/SUBA100 (double cloth) manufactured by Rodel Inc., and Surfinxxx-5 and Surfin000 manufactured by Fujimi Inc., among others. SUBA800, Surfinxxx-5 and Surfin000 are non-woven fabrics bonded by polyurethane resin, while IC-1000 is made of rigid foam polyurethane (single layer). Foamed polyurethane is porous and has a large number of fine grooves or pores formed in its surface.

The top ring 1 is connected to the top ring driving shaft 11 through the universal joint 10 , and the top ring driving shaft 11 is connected with a top ring cylinder 111 fixed on the top ring head cover 110 . The top ring cylinder 111 is used to vertically move the top ring drive shaft 11 to thereby integrally lift the top ring 1 and press the snap ring 3 held at the lower end of the top ring body 2 against the polishing table 100 . The top ring cylinder 111 is connected to the pressure regulating unit 120 through the regulator R1. The pressure regulating unit 120 is used to regulate the pressure by supplying a pressurized fluid, such as compressed air, from a compressed air source (not shown), or by creating a vacuum with a pump (not shown), or the like. The pressure adjusting unit 120 may adjust the fluid pressure of the pressurized fluid to be supplied to the top ring cylinder 111 using the regulator R1. Therefore, the pressing force of the snap ring 3 pressing the polishing pad 101 can be adjusted.

The top ring drive shaft 11 is connected to the rotating sleeve 112 by a key (not shown). The rotary sleeve 112 has a timing pulley 113 fixedly provided on its peripheral portion. The top ring motor 114 is fixed on the top ring head cover 110 , and the synchronous pulley 113 is connected with a synchronous pulley 116 installed on the top ring motor 114 through a synchronous belt 115 . Therefore, when the top ring motor 114 is energized and rotated, the rotating sleeve 112 and the top ring drive shaft 11 are rotated synchronously with each other through the timing pulley 116 , the timing belt 115 and the timing pulley 113 to thereby rotate the top ring 1 . The top ring head cover 110 is supported by a top ring drive shaft 117 which is rotatably supported by a bracket (not shown).

Next, the top ring 1 serving as the substrate holding device according to the first embodiment of the present invention will be described in detail. Fig. 2 is a vertical sectional view of the top ring 1 according to the first embodiment.

As shown in FIG. 2, the top ring 1 serving as a substrate holding device includes a cylindrical container-shaped top ring body 2 and an annular snap ring 3 fixed on the lower end of the top ring body 2, wherein the top ring body 2 has a of accommodation space. The top ring body 2 is made of high-strength and high-rigidity materials, such as metal or ceramics. The snap ring 3 is made of highly rigid resin, ceramics, or the like.

The top ring body 2 includes a cylindrical container-shaped casing 2a, an annular pressing piece support 2b put into the cylindrical portion of the casing 2a, and an annular seal 2c put in a groove formed on the peripheral edge of the upper surface of the casing 2a. . The snap ring 3 is fixed on the lower end of the shell 2 a of the top ring body 2 . The snap ring 3 has a lower portion protruding radially inwards. The snap ring 3 can be integrally formed with the top ring body 2 .

The top ring drive shaft 11 is located on the middle part of the casing 2 a of the top ring body 2 , and the top ring body 2 is connected with the top ring drive shaft 11 through a universal joint 10 . The universal joint 10 has a spherical bearing mechanism and a rotation transmission mechanism for transmitting the rotation of the top ring drive shaft 11 to the top ring body 2, wherein the top ring body 2 and the top ring drive shaft 11 can be rotated through the spherical bearing mechanism. inclined relative to each other. The ball bearing mechanism and the rotation transmission mechanism transmit the pressing force and the rotating force from the top ring drive shaft 11 to the top ring body 2, while allowing the top ring body 2 and the top ring drive shaft 11 to tilt relative to each other.

The spherical bearing mechanism includes a hemispherical concave groove 11a defined in the center of the lower surface of the top ring drive shaft 11, a hemispherical concave groove 2d defined in the center of the upper surface of the housing 2a, and a hemispherical concave groove 2d defined in the center of the upper surface of the housing 2a, and made of a high hardness material such as ceramics and The bearing ball 12 is placed between the concave grooves 11a and 2d. The rotation transmission mechanism includes a driving pin (not shown) fixed on the driving shaft 11 and a driven pin (not shown) fixed on the housing 2a. Even if the top ring body 2 is tilted with respect to the top ring drive shaft 11, since the driving pin and the driven pin can move vertically relative to each other, the driving pin and the driven pin remain engaged with each other while the contact points are displaced. Thus, the rotation transmission mechanism reliably transmits the torque of the top ring drive shaft 11 to the top ring body 2 .

The top ring body 2 and the snap ring 3 integrally fixed on the top ring body 2 define a receiving space therein. Inside the receiving space there are an annular retaining ring 5 and a disc-shaped chuck 6 serving as a vertically movable part. The chuck 6 is vertically movable in a receiving space formed inside the top ring body 2 . The chuck can be made of metal. However, when measuring the thickness of the film formed on the surface of the semiconductor wafer by using the stray current method in a state where the polished semiconductor wafer is held by the top ring, the chuck 6 should preferably be made of a non-magnetic substance such as an insulating material such as PPS, PEEK, Made of fluororesin or ceramics.

Between the retaining ring 5 and the top ring body 2 there is a pressure piece 13 comprising an elastic membrane. The pressing piece 13 has a radially outer edge sandwiched between the housing 2 a and the pressing piece support 2 b of the top ring body 2 and a radially inner edge sandwiched between the seat ring 5 and the chuck 6 . The top ring body 2 , the chuck 6 , the seat ring 5 and the pressure piece 13 jointly define a pressure chamber 21 in the top ring body 2 . As shown in FIG. 2 , the pressure chamber 21 communicates with a fluid passage 32 including tubes, connectors, and the like. The pressure chamber 21 is connected to the pressure regulating unit 120 through the regulator R2 on the fluid channel 32 . The pressing sheet 13 is made of a strong and durable rubber material such as ethylene propylene diene monomer (EPDM), urethane rubber or silicone rubber.

When the pressing piece 13 is made of an elastic material such as rubber, if the pressing piece 13 is fixedly clamped between the snap ring 3 and the top ring body 2, due to the elastic deformation of the pressing piece 13 as an elastic material, it cannot A desired horizontal surface is maintained on the lower surface of the snap ring 3 . To avoid such drawbacks, in the present embodiment, the pressing sheet 13 is sandwiched between the casing 2a of the top ring body 2 and the pressing sheet support 2b provided as a detachable part. The snap ring 3 can move vertically relative to the top ring body 2 , or the snap ring 3 can have a structure that can press the polishing surface 101a independently of the top ring body 2 . In this case, the pressing piece 13 does not necessarily have to be fixed in the above-described manner.

An annular edge film (elastic member) 7 is provided on the outer peripheral edge of the chuck 6 and is in contact with the outer peripheral edge of the semiconductor wafer W held by the top ring 1 . The top end of the edge film 7 is sandwiched between the outer circumferential edge of the chuck 6 and the annular edge ring 4 , whereby the edge film 7 is attached to the chuck 6 .

The edge membrane 7 has a pressure chamber 22 formed therein, and the pressure chamber 22 communicates with a fluid passage 33 including pipes, connectors and the like. The pressure chamber 22 is connected to the pressure regulating unit 120 through a regulator R3 provided on the fluid channel 33 . The edge film 7 is made of high-strength and durable rubber material such as EPDM, urethane rubber, silicone rubber, like the pressing sheet 13 . The rubber material of the edge film 7 preferably has a hardness (Durometer) of 20-60.

When the semiconductor wafer W is polished, the semiconductor wafer W is turned by the rotation of the top ring 1 . The contact area of the edge film 7 with the semiconductor wafer W is very small, and thus sufficient rotational torque to the semiconductor wafer W cannot easily be transmitted. Then, an annular intermediate (empty) bladder 19 is fixed on the lower surface of the chuck 6 to be in close contact with the semiconductor wafer W, so that sufficient torque can be transmitted to the semiconductor wafer W through the intermediate bladder 19 . The middle bladder 19 is located radially inside the edge film 7 and contacts the semiconductor wafer W with a contact area large enough to transmit sufficient torque to the semiconductor wafer W.

The middle airbag 19 includes an elastic film 91 in contact with the upper surface of the semiconductor wafer W and an airbag holder 92 for detachably holding the elastic film 91 in place. An annular groove 6a is formed on the lower surface of the chuck 6, and the airbag bracket 92 is fixedly mounted on the annular groove 6a by screws (not shown). The top end of the elastic film 91 constituting the middle air bag 19 is sandwiched between the annular groove 6 a and the air bag holder 92 so that the elastic film 91 is detachably mounted on the lower surface of the chuck 6 .

The central airbag 19 has a pressure chamber 23 defined therein by an elastic membrane 91 and an airbag holder 92 . The pressure chamber 23 communicates with a fluid channel 34 including tubing, connectors, and the like. The pressure chamber 23 is connected to the pressure regulating unit 120 through a regulator R4 provided on the fluid channel 34 . Like the pressing sheet 13, the elastic film 91 is made of a strong and durable rubber material such as ethylene propylene diene monomer (EPDM), urethane rubber, silicone rubber.

An annular space defined by the edge film 7 , the intermediate bladder 19 , the semiconductor wafer W and the chuck 6 serves as the pressure chamber 24 . The pressure chamber 24 communicates with a fluid passage 35 including tubing, connectors, and the like. The pressure chamber 24 is connected to the pressure regulating unit 120 through a regulator R5 provided on the fluid channel 35 .

An annular space defined by the intermediate bladder 19 , the semiconductor wafer W and the chuck 6 serves as the pressure chamber 25 . The pressure chamber 25 communicates with a fluid passage 36 including tubing, connectors, and the like. The pressure chamber 25 is connected to the pressure regulating unit 120 through a regulator R6 provided on the fluid channel 36 . The fluid passages 32, 33, 34, 35 and 36 are respectively connected to the regulators R2-R6 through rotary joints (not shown) provided on the top end of the top ring head cover 110.

A cleaning liquid passage 51 in the form of an annular groove is formed in the sealing member 2c of the top ring body 2 near the outer peripheral edge of the upper surface of the housing 2a. The cleaning liquid channel 51 communicates with the fluid channel 30 and supplies cleaning liquid such as pure water through the fluid channel 30 . A plurality of communication holes 53 protrude from the washing liquid passage 51 and pass through the housing 2a and the pressing plate support 2b. The communication hole 53 communicates with a small gap G between the outer peripheral surface of the edge film 7 and the inner peripheral surface of the snap ring 3 .

Since the small gap G is formed between the outer circumferential surface of the edge film 7 and the snap ring 3, the components including the bracket ring 5, the chuck 6, and the edge film 7 mounted on the chuck 6 are relatively relative to the top ring body 2 and the snap ring 3. The snap ring 3 can move vertically in a floating manner. The chuck 6 has a plurality of protrusions 6c protruding radially outward from its outer peripheral edge. When the protrusion 6c is engaged with the upper surface of the inwardly projecting portion of the snap ring 3, the downward movement of the components including the chuck 6 is restricted at a specific position.

Next, the intermediate airbag 19 will be described in detail with reference to FIGS. 3A-3C . 3A-3C are enlarged cross-sectional views of the middle airbag shown in FIG. 2 .

As shown in FIG. 3A, the elastic membrane 91 of the middle airbag 19 has a middle contact portion 91b, the middle contact portion 91b has a flange 91a protruding outward, and an extension portion 91d extending outward from a base portion 91c of the flange 91a to extend outward. A groove 93 is formed between the portion 91d and the flange 91a, and a connecting portion 91e is connected to the chuck 6 through the airbag bracket 92 . The extension portion 91d extends outward from the base of the flange 91a to a position inside the top end of the flange 91a, and the connection portion 91e extends upward from the outer end of the extension portion 91d. The flange 91a, the intermediate contact portion 91b, the connection portion 91e and the extension portion 91d are integrally formed with each other and made of the same material. An opening 91f is formed in the central portion of the intermediate contact portion 91b.

With this structure, in the case where the chuck 6 is lifted for polishing after the semiconductor wafer comes into close contact with the intermediate contact portion 91b of the intermediate bladder 19 (see FIG. 3B ), the upward force of the connecting portion 91e is converted by the extending portion 91d into Horizontal or oblique force, the converted force is exerted on the base 91c of the flange 91a (see FIG. 3C). Therefore, the upward force applied to the base portion 91c of the flange 91a can be very small so that no excessive upward force is applied to the contact portion 91b. Therefore, a vacuum is not formed in the vicinity of the base portion 91c, whereby a uniform polishing rate can be obtained over the entire surface of the intermediate contact portion 91b except the flange 91a. In this case, the thickness of the connecting portion 91e or the length of the flange 91a may vary between the connecting portion located on the radially inner side and the connecting portion located on the radially outer side. In addition, the length of the extension portion 91d may vary between an extension portion located on the radially inner side and an extended portion located on the radially outer side. In addition, the thickness of the flange 91a may vary depending on the type of film formed on the semiconductor wafer to be polished or the type of polishing pad. When the resistance or polishing torque transmitted to the semiconductor wafer is large, the thickness of the flange 91a should preferably be larger in order to avoid distortion of the flange 91a.

The edge film 7 according to this embodiment will be described in detail below with reference to FIGS. 4A-4C . 4A is a sectional view of the overall structure of the edge film according to the first embodiment of the present invention, and FIGS. 4B and 4C are partial cross-sectional views of the substrate holding device shown in FIG. 2 .

The edge film (elastic member) 7 according to the present embodiment includes an annular contact portion 8 in contact with the outer peripheral edge of the semiconductor wafer W and an annular peripheral wall 9 extending upward from the contact portion 8 and connected to the chuck 6 . The peripheral wall 9 includes an outer peripheral wall 9a and an inner peripheral wall 9b located radially inside the outer peripheral wall 9a. The contact portion 8 has an outer shape extending radially inward from the peripheral wall 9 (ie, the outer peripheral wall 9 a and the inner peripheral wall 9 b ). The contact portion 8 has a slit 18 extending in the circumferential direction between the outer peripheral wall 9a and the inner peripheral wall 9b. In particular, the slit 18 divides the contact portion 8 into an outer contact portion 8 a and an inner contact portion 8 b at a position between the outer peripheral wall 9 a and the inner peripheral wall 9 b.

As shown in FIGS. 4B and 4C , an outer peripheral wall 9 a and an inner peripheral wall 9 b extend upward along the outer peripheral surface and the inner peripheral surface of the annular edge ring 4 , respectively. The upper ends of the outer peripheral wall 9a and the inner peripheral wall 9b are sandwiched between the chuck 6 and the upper surface of the edge ring 4, respectively. The edge ring 4 is held on the chuck 6 by screws (not shown), so that the edge film 7 is detachably attached to the chuck 6 . The fluid channel 33 extends vertically through the edge ring 4 and opens on the lower surface of the edge ring 4 . Therefore, the annular pressure chamber 22 defined by the edge ring 4, the edge membrane 7 and the semiconductor wafer W communicates with the fluid channel 33, and is connected with the pressure regulating unit 120 through the fluid channel 33 and the regulator R3.

The peripheral wall 9 has a stretchable portion 40 that can expand and contract vertically, that is, substantially perpendicularly to the semiconductor wafer W. As shown in FIG. More specifically, the peripheral wall 9a constituting the peripheral wall 9 has a stretchable portion 40a that can expand and contract vertically. The stretchable portion 40a has a structure such that a part of the outer peripheral wall 9a is folded inwardly and further outwardly to form a folded-back portion extending in the circumferential direction. The telescoping portion 40a is located adjacent to the outer contact portion 8a and below the edge ring 4 . The inner peripheral wall 9b constituting the peripheral wall 9 also has a stretchable portion 40b that can expand and contract vertically. The expandable portion 40b has a structure such that a portion of the inner peripheral wall 9b near its lower end is folded inward in the circumferential direction. Since the stretchable parts 40a, 40b are respectively arranged on the outer peripheral wall 9a and the inner peripheral wall 9b, the outer peripheral wall 9a and the inner peripheral wall 9b can freely expand and contract to a large extent, and the contact part 8 (ie, the outer contact part 8a and the inner contact part 8b) remains unchanged. Therefore, as shown in FIG. 4C, when the chuck 6 moves upward, the stretchable portions 40a, 40b expand to follow the movement of the chuck 6, so that the contact area between the edge film 7 and the semiconductor wafer W remains unchanged.

The pressure chamber 21 located above the chuck 6 and the pressure chambers 22, 23, 24 and 25 are supplied with a pressurized fluid such as compressed air, or via fluid channels 32, 33, 34, 35 connected to the respective pressure chambers. and 36 create atmospheric pressure or vacuum in the pressure chambers 21, 22, 23, 24 and 25. In particular, regulators R2-R6 disposed on fluid passages 32, 33, 34, 35, and 36, respectively, can adjust the pressure of the pressurized fluid supplied to corresponding pressure chambers 21, 22, 23, 24, and 25, respectively. Thereby, it is possible to independently control the pressure of the pressure chambers 21 , 22 , 23 , 24 and 25 , or to generate normal pressure or vacuum within the pressure chambers 21 , 22 , 23 , 24 and 25 independently.

As described above, the edge film 7 has the radially inwardly extending contact portion 8 (inner contact portion 8b) at its lower end, and the intermediate airbag 19 has the flange 91a at its lower end. The contact portion 8 (inner contact portion 8 b ) and the flange 91 a come into close contact with the semiconductor wafer W by the pressurized fluid supplied to the pressure chambers 22 , 23 and 24 . Accordingly, the pressurized fluid within the pressure chambers 22 , 23 and 24 does not flow under the edge membrane 7 and the intermediate bladder 19 . Specifically, the contact portion 8 and the flange 91a are pressed against the semiconductor wafer W by the pressurized fluid, whereby the edge film 7 and the intermediate bladder 19 are kept in close contact with the semiconductor wafer W. Therefore, the pressure in each of the pressure chambers 22, 23, and 24 can be stably controlled.

In this case, the pressurized fluid supplied to the pressure chambers 22, 23, 24, and 25 or the atmosphere supplied to the above-mentioned pressure chambers when normal pressure is generated therein can be independently temperature-controlled. With this structure, the temperature of a workpiece such as a semiconductor wafer can be directly controlled from the backside of the surface to be polished. In particular, when the temperature of each pressure chamber is individually controlled, the chemical reaction speed in the present chemical polishing process CMP can be controlled.

Next, the operation of the top ring 1 thus constructed will be described in detail.

In the polishing apparatus having the above structure, when the semiconductor wafer W is carried into the polishing apparatus, the top ring 1 is entirely moved to the transfer position where the semiconductor wafer W is transferred. In the case where the diameter of the semiconductor wafer W is 200 mm, the pressure adjustment unit 120 communicates with the pressure chamber 23 through the fluid passage 34 . In the case where the diameter of the semiconductor wafer W is 300 mm, the pressure adjustment unit 120 communicates with the pressure chamber 24 through the fluid passage 35 . Then, the pressure chamber 23 or 24 is evacuated by the pressure adjusting unit 120 so that the semiconductor wafer W is sucked to the lower end of the top ring 1 under vacuum by the suction action of the pressure chamber 23 or 24 . After the semiconductor wafer W is sucked onto the top ring 1 , the top ring as a whole is moved to a position above the polishing table 100 having the polishing surface 101 a on the polishing pad 101 . The outer peripheral edge of the semiconductor wafer W is held by the snap ring 3, whereby the semiconductor wafer W does not come off the top ring 1, or the semiconductor wafer W does not slip.

After that, the attractive force applied to the semiconductor wafer W by the pressure chamber 23 or 24 is stopped. At about the same time, the top ring cylinder 111 connected to the top ring drive shaft 11 is actuated to press the snap ring 3 held under the top ring 1 against the polishing surface 101a of the polishing table 100 with a predetermined pressure. Then, pressurized fluid is fed into the pressure chamber 21 to move the chuck 6 downward, thereby pressing the edge film 7 and the intermediate bladder 19 against the semiconductor wafer W. In this way, the lower surface of the edge film 7 and the intermediate air pocket 19 can come into close contact with the upper surface of the semiconductor wafer. In this state, pressurized fluids having respective different pressures are input into the pressure chambers 22, 23, 24, and 25, respectively, so that the chuck is moved upward, and at the same time, the semiconductor wafer W is pressed against the polishing surface of the polishing table 100. 101a on. At this time, the stretchable portions 40a, 40b on the edge film 7 are stretched to follow the upward movement of the chuck 6 . Therefore, the contact area between the lower surface of the edge film 7 , that is, the contact portion 8 and the outer peripheral edge of the semiconductor wafer W can remain unchanged. The polishing liquid supply nozzle 102 supplies the polishing liquid Q on the polishing surface 101 a of the polishing pad 101 in advance, whereby the polishing liquid Q is held on the polishing pad 101 . Thus, the semiconductor wafer W is polished with the polishing liquid Q present between its (lower) surface to be polished and the polishing pad 101 .

By the top ring 1 serving as the substrate holding means according to the present embodiment, since the contact area between the edge film 7 and the outer peripheral edge of the semiconductor wafer W remains unchanged, it is possible to prevent stress applied on the outer peripheral edge of the semiconductor wafer W. The pressing force is changed. Therefore, the entire surface including the outer peripheral edge of the semiconductor wafer W can be pressed against the polishing surface 101a with a uniform pressing force. Therefore, a decrease in the polishing rate at the outer peripheral edge of the semiconductor wafer W can be prevented. In addition, it is also possible to prevent the polishing rate from increasing at a region located radially inward of the outer peripheral edge of the semiconductor wafer W. In particular, when the diameter of the semiconductor wafer W is 200 mm, the polishing rate at a region approximately 20 mm from the outer peripheral edge of the semiconductor wafer W can be prevented from increasing. When the diameter of the semiconductor wafer W is 300 mm, the polishing rate at a region approximately 25 mm from the outer peripheral edge of the semiconductor wafer W can be prevented from increasing.

The circumferentially extending slit 18 formed in the contact portion 8 of the edge film 7 is effective in improving the stretchability of the peripheral wall 9 (the outer peripheral wall 9 a and the inner peripheral wall 9 b ) in the downward direction. Therefore, even when the pressure of the pressurized fluid supplied to the pressure chamber 22 is small, the contact area between the edge film 7 and the semiconductor wafer W can remain unchanged. Thereby, the semiconductor wafer W can be pressed with a smaller pressing force.

Local regions of the semiconductor wafer W below the pressure chambers 22 , 23 , 24 and 25 are pressed against the polishing surface 101 a by the pressure of the pressurized fluid supplied to the pressure chambers 22 , 23 , 24 and 25 . Therefore, the pressures of the pressurized fluids supplied to the pressure chambers 22, 23, 24, and 25 are controlled independently of each other, so that the entire surface of the semiconductor wafer W can be pressed against the polishing surface with uniform pressing force. Therefore, a uniform polishing rate can be obtained over the entire surface of the semiconductor wafer W. Likewise, regulator R2 adjusts the pressure of the pressurized fluid supplied to pressure chamber 21 to vary the pressure applied to polishing pad 101 by snap ring 3 . In this way, the pressure applied to the polishing pad 101 by the snap ring 3 and the pressure applied by the respective pressure chambers 22, 23, 24 and 25 to press the semiconductor wafer W against the polishing pad 101 are properly adjusted during polishing. , to control the polishing profile of the semiconductor wafer W. The semiconductor wafer W has an area where a pressing force is applied by the pressurized fluid through the contact portion of the intermediate bladder 19, and an area where the pressure of the pressurized fluid is directly applied. The pressures exerted on these areas are equal to each other.

As described above, the pressure applied by the top ring cylinder 111 to press the snap ring 3 against the polishing pad 101 and the pressure applied by the pressurized fluid input to the pressure chambers 22, 23, 24 and 25 press the semiconductor wafer W against the polishing pad 101. The pressure on the pad 101 is properly adjusted to polish the semiconductor wafer W. When the polishing process of the semiconductor wafer W is completed, the supply of pressurized fluid to the pressure chambers 22, 23, 24, and 25 is stopped, and the pressure of the pressure chambers 22, 23, 24, and 25 is lowered to atmospheric pressure. Thereafter, the pressure chamber 23 or the pressure chamber 24 is evacuated to generate a negative pressure therein so that the semiconductor wafer W is adsorbed onto the lower surface of the top ring 1 again. At this time, atmospheric pressure or negative pressure is generated in the pressure chamber 21 . This is because the semiconductor wafer W is partially pressed against the polishing surface 101a by the lower surface of the chuck 6 if the pressure chamber 21 is kept at a high pressure.

After the semiconductor wafer W is adsorbed in the above-mentioned manner, the top ring 1 is moved as a whole to the transfer position, and then a fluid (for example, a pressurized fluid or a mixture of nitrogen and pure water) is sprayed from the fluid channel 35 to the semiconductor wafer W so as to flow from the top ring 1 to the semiconductor wafer W. The semiconductor wafer W is released from the ring 1 .

The polishing liquid Q for polishing the semiconductor wafer W tends to flow into the small gap G between the outer peripheral surface of the edge film 7 and the snap ring 3 . If the polishing liquid Q is firmly deposited in the gap G, it will hinder the smooth vertical movement of the bracket ring 5 , the chuck 6 and the edge film 7 relative to the top ring body 2 and the snap ring 3 . In order to avoid this disadvantage, a cleaning liquid, such as pure water, is fed into the annular cleaning liquid channel 51 through the fluid channel 30 . Therefore, pure water is input into the space above the gap G through the plurality of communication holes 53, thereby cleaning the gap G to prevent the polishing liquid Q from being firmly deposited in the gap G. Preferably, the pure water is input after the polished semiconductor wafer W is detached, and until the next semiconductor wafer to be polished is attracted onto the top ring 1 .

A substrate holding device according to a second embodiment of the present invention will be described below with reference to FIGS. 5A and 5B. 5A and 5B are partial cross-sectional views of a substrate holding device according to a second embodiment of the present invention; the structural details of the substrate holding device according to the second embodiment are the same as those of the substrate holding device according to the first embodiment , which will not be described below.

As shown in FIG. 5A, the telescopic portion 40a formed in the outer peripheral wall 9a is located near the top end of the outer peripheral wall 9a. The edge ring 4 has an annular receiving groove 4a for receiving the telescoping portion 40a therein. The accommodation groove 4 a is formed in the outer circumferential surface of the edge ring 4 and extends in the circumferential direction of the edge ring 4 . As shown in FIG. 5B , the width of the receiving groove 4 a is large enough to allow the stretchable portion 40 a not to contact the edge ring 4 even when stretched downward. The edge ring 4 has a pressing member 45 for pressing the outer contact portion 8a against the outer peripheral edge of the semiconductor wafer W in contact with the upper surface of the outer contact portion 8a (contact portion 8). A plurality of radially extending grooves 46 are formed on the lower surface of the pressing member 45 . The pressurized fluid input into the pressure chamber 22 through the fluid passage 33 is supplied through the groove 46 to the upper surface of the outer contact portion 8a constituting the contact portion. In this embodiment, the pressing part 45 is integrally formed with the edge ring 4 . However, the pressing part 45 can also be separated from the edge ring 4 .

The operation of the substrate holding device having the above-mentioned structure according to the present embodiment will be described below. The operation details of the substrate holding device according to the second embodiment of the present invention are the same as those of the substrate holding device according to the first embodiment of the present invention, and will not be described below.

The semiconductor wafer W is placed on the polishing surface 101a by the top ring 1, and then pressurized fluid is input into the pressure chamber 21 to move the chuck 6 and the edge ring 4 downward. At this time, the lower surface of the pressing member 45 is in contact with the upper surface of the outer contact portion 8a, so that the pressing member 45 presses the outer contact portion 8a against the semiconductor wafer W with a predetermined pressure. The edge film 7 and the semiconductor wafer W thus remain in sufficiently close contact with each other. In this state, pressurized fluid is fed into the pressure chambers 22 , 23 , 24 and 25 .

The pressurized fluid input into the pressure chamber 22 through the fluid passage 33 is quickly supplied through the groove 46 to the upper surface of the outer contact portion 8a. Therefore, the pressurized fluid presses the outer contact portion 8 a against the semiconductor wafer W at the same time that the pressurized fluid is input into the pressure chamber 22 . As pressurized fluid is fed into the pressure chambers 22, 23, 24 and 25, the chuck 6 moves upward and the telescoping portion 40a of the outer peripheral wall 9a and the telescoping portion 40b of the inner peripheral wall 9b are stretched. At this time, the stretchable portion 40 a deforms inside the receiving groove 4 a formed in the edge ring 4 . Therefore, the stretchable portion 40a is prevented from coming into contact with the edge ring 4, thereby ensuring its excellent stretchability. In this way, the semiconductor wafer W is polished in a state of being pressed against the polishing surface 101 a by the pressure chambers 22 , 23 , 24 and 25 .

According to the substrate holding device having the above structure, the pressing member 45 can bring the edge film 7 and the semiconductor wafer W into close contact. Therefore, the pressurized fluid input into the pressure chamber 22 can be prevented from leaking. In addition, the pressurized fluid can be quickly supplied to the upper surface of the outer contact portion 8 a through the groove 46 . Therefore, the pressurized fluid can start pressing the outer contact portion 8 a against the semiconductor wafer W at the same time as the edge film 7 is pressed by the pressing member 45 . In addition, the telescopic portion 40a is located near the outer peripheral wall 9a. Therefore, the extensibility of the peripheral wall 9a can be improved, and the peripheral wall 9a is prevented from twisting in the circumferential direction, so that the edge film 7 can always function in the same way.

An edge film 7 according to a third embodiment of the present invention will be described below with reference to FIGS. 6A and 6B . 6A is a partial cross-sectional view of a substrate holding device according to a third embodiment of the present invention, and FIG. 6B is a partial cross-sectional view of another structure of an edge film in the third embodiment of the present invention. The structure and operation details of the substrate holding device according to the third embodiment of the present invention are the same as those of the substrate holding device according to the second embodiment of the present invention, and will not be described below.

As shown in FIG. 6A, the outer contact portion 8a constituting the contact portion 8 to be pressed by the pressing member 45 has a thick portion 48 on its upper surface. The thick portion 48 extends in the circumferential direction of the outer contact portion 8a, and has a substantially arcuate (bow) cross-section. A reinforcing member 50 for reinforcing the strength of the outer contact portion 8a is embedded in the outer contact portion 8a. The pressing member 45 has a step on its lower surface to form a first pressing surface 45a and a second pressing surface 45b located above the first pressing surface 45a. The first pressing surface 45 a is in contact with the outer contact portion 8 a , while the second pressing surface 45 b is in contact with the thick portion 48 . The first pressing surface 45a and the second pressing surface 45b have a plurality of radially extending grooves 46a and 46b therein, respectively. As in the second embodiment, the grooves 46a, 46b allow the pressurized fluid to start pressing the outer contact portion 8a against the semiconductor wafer W at the same time as the edge film 7 is pressed by the pressing member 45 .

As described above, according to the present embodiment, the outer contact portion 8 a to be pressed by the pressing member 45 has the thick portion 48 , and the reinforcing member 50 is embedded in the outer contact portion 48 . With this structure, the mechanical strength of the outer contact portion 8a can be enhanced. Therefore, when the external contact portion 8a is pressed against the semiconductor wafer W by the pressing member 45, the external contact portion 8a is prevented from twisting in the circumferential direction. Therefore, the edge film 7 and the semiconductor wafer W can be kept in close contact with each other, thereby preventing leakage of the pressurized fluid.

In addition, since the thick portion 48 has a substantially arc-shaped cross-section, the polishing fluid that has entered the pressure chamber 22 is less likely to be firmly deposited at the thick portion 48 . In addition, the lower surface of the pressing member 45 , that is, the second pressing surface 45 b and the thick portion 48 are not kept in close contact with each other, thereby allowing the pressing member 45 to easily come out of contact with the thick portion 48 . The contact portion 8 may optionally be reinforced with one of the thick portion 48 or the reinforcing member 50 . As shown in FIG. 6B, the thick portion 48 may have a triangular cross-section.

A substrate holding device according to a fourth embodiment of the present invention will be described below with reference to FIG. 7 . 7 is a partial cross-sectional view of a substrate holding device according to a fourth embodiment of the present invention. The structure and operation details of the substrate holding device according to the fourth embodiment of the present invention are the same as those of the substrate holding device according to the third embodiment of the present invention, and will not be described below. The substrate holder according to the fourth embodiment differs from the substrate holder according to the third embodiment in that the fluid supply port for supplying pressurized fluid to the upper surface of the contact portion is provided on the edge ring instead of on the edge ring. Grooves are provided in the lower surface of the pressing member.

As shown in FIG. 7 , the edge ring 4 has a through hole 180 formed therein and communicated with the fluid passage 33 . The through hole 180 has three openings, a first opening 180a opening to the outer contact portion 8a (contact portion 8) serving as a fluid supply port, a second opening 180b opening to the retractable portion 40b of the inner peripheral wall 9b, and an opening at the edge ring. The third opening 180c opened at the outer peripheral surface of the 4. The pressurized fluid introduced into the through hole 180 through the fluid channel 33 is divided into three streams within the edge ring 4 . Specifically, the pressurized fluid constituting the first stream is supplied from the first opening 180a to the upper surface of the outer contact portion 8a, the pressurized fluid constituting the second stream is supplied from the second opening 180b to the retractable portion 40b of the inner peripheral wall 9b, And the pressurized fluid constituting the third stream is supplied from the third opening 180c to the back side of the outer peripheral wall 9a.

With this structure, the pressurized fluid is supplied to the upper surface of the outer contact portion 8 a while the outer contact portion 8 a is pressed by the pressing member 45 . Therefore, the pressurized fluid can start pressing the outer contact portion 8 a (contact portion 8 ) while the edge film 7 is pressed by the pressing member 45 as in the third embodiment described above.

An edge film according to a fifth embodiment of the present invention will be described below with reference to FIGS. 8A and 8B. 8A is a cross-sectional view of an edge film according to a fifth embodiment of the present invention, and FIG. 8B is a cross-sectional view of another structure of the edge film in the fifth embodiment of the present invention.

In the edge film according to the first embodiment, the stretchable portion is formed by folding a part of the peripheral wall in the circumferential direction. Alternatively, as shown in FIG. 8A , the peripheral wall 9 may be made of a softer material than the contact portion 8 so as to provide the stretchable portion 40 . Alternatively, as shown in FIG. 8B , the peripheral wall 9 may be thinner than the contact portion 8 so as to provide a stretchable portion 40 . According to these structures, the peripheral wall 9 can expand and contract vertically, that is, perpendicular to the semiconductor wafer, just like the expandable portion according to the above-described embodiments.

An edge film according to a sixth embodiment of the present invention will be described below with reference to FIGS. 9A and 9B. 9A is a cross-sectional view of an edge film according to a sixth embodiment of the present invention, and FIG. 9B is a reference view illustrating stretchability of the edge film according to the sixth embodiment of the present invention. The edge film according to the present embodiment has the same basic structure as the edge film according to the second embodiment.

As shown in FIG. 9A , the folded portion 71 of the expandable portion 40 and the connecting portion 72 between the peripheral wall 9 and the contact portion 8 have substantially arc-shaped cross sections, respectively. As shown in FIG. 9B, in general, if the connecting portion between the parts has an angular (pointed) cross-section, the angular cross-section remains the original shape even after the parts are stretched vertically, so that the extensibility of the parts is affected. limit. On the other hand, if the connecting portion between the parts has a substantially arc-shaped cross-section, the connecting portion can be deformed flexibly, thereby providing the parts with excellent stretchability. Therefore, with the above structure, the peripheral wall 9 including the stretchable portion 40 can be smoothly and smoothly stretched.

An edge film according to a seventh embodiment of the present invention will be described below with reference to FIGS. 10A-10E. 10A is a cross-sectional view of an edge film according to a seventh embodiment of the present invention, and FIGS. 10B-10E are respectively cross-sectional views of another structure of the edge film in the seventh embodiment of the present invention. The edge film according to the present embodiment has the same basic structure as the edge film according to the second embodiment.

Generally, when a semiconductor wafer is polished, frictional forces are generated between the semiconductor wafer held by the top ring and the polishing surface. Therefore, the edge film may be twisted in its circumferential direction, whereby close contact between the edge film and the semiconductor wafer tends to be weakened. Therefore, in the edge film 7 shown in FIGS. 10A-10E , in order to prevent the edge film from being twisted, a part of the peripheral wall 9 located below the stretchable portion 40 has enhanced mechanical strength.

In particular, FIG. 10A shows an edge film 7 in which a part of the peripheral wall 9 located below the stretchable portion 40 is made of a harder material than the contact portion 8 . FIG. 10B shows an edge film 7 in which a part of the peripheral wall 9 located below the stretchable portion 40 is thicker than the contact portion 8 . FIG. 10C shows an edge film 7 in which a hard member 96 harder than the edge film 7 is embedded in a part of the peripheral wall 9 located below the stretchable portion 40 . FIG. 10D shows an edge film 7 in which a hard member 96 harder than the edge film 7 is fixed to a part of the peripheral wall 9 located below the expandable portion 40 . FIG. 10E shows an edge film 7 in which a part of the peripheral wall 9 located below the stretchable portion 40 is coated with a hard material 97 harder than the edge film 7 . The hard part 96 preferably includes a metal having excellent rust resistance such as stainless steel or resin. The edge film 7 having the above structure can prevent twisting in its circumferential direction when the semiconductor wafer is polished, so that the edge film 7 and the semiconductor wafer W are kept in close contact with each other.

A substrate holding device according to an eighth embodiment of the present invention will be described below with reference to FIGS. 11A and 11B . 11A and 11B are partial cross-sectional views of a substrate holding device according to an eighth embodiment of the present invention. The structure and operation details of the substrate holding device according to the eighth embodiment of the present invention are the same as those of the substrate holding device according to the first embodiment of the present invention, and will not be described below.

As shown in FIG. 11A, the outer peripheral wall 9a is folded radially inward in its circumferential direction near the outer contact portion 8a, thereby forming a stretchable portion 40a. The telescoping portion 40a is located below the edge ring 4 . There is a protective member 190 radially outside of the outer peripheral wall 9a (peripheral wall 9). The protection member 190 serves to prevent the edge film 7 and the snap ring 3 from contacting each other. The protection unit 190 is located on the outer peripheral edge of the chuck 6 and integrally formed with the chuck 6 . Alternatively, the protection unit 190 can also be provided as a separate component from the chuck 6 . With this structure, the edge film 7 and the snap ring 3 can be prevented from contacting each other, thereby allowing the chuck 6 to move vertically smoothly.

Next, a substrate holding device according to a ninth embodiment of the present invention will be described. The structure and operation details of the substrate holding device according to the ninth embodiment of the present invention are the same as those of the substrate holding device according to the first embodiment of the present invention, and will not be described below.

The outer contact portion 8a and the inner contact portion 8b constituting the contact portion 8 have a plurality of fine protrusions and recesses on their upper surfaces. Such protrusions and recesses are preferably formed by, for example, a graining process. The roughening process is a process in which regular or irregular protrusions and recesses are formed on the surface of the workpiece to roughen the surface. With such a structure having said protrusions and recesses on the upper surfaces of the outer contact portion 8a and the inner contact portion 8b, the attachment of the inner contact portion 8b to the chuck 6 can be weakened. Therefore, when the chuck 6 moves upward, the inner contact portion 8b of the edge film 7 is prevented from moving upward together with the chuck 6 . Furthermore, when the pressing member 45 is in contact with the outer contact portion 8a as described in the second embodiment, the pressing member 45 can be easily disengaged from the outer contact portion 8a. In this embodiment, the lower surfaces of the outer contact portion 8a and the inner contact portion 8b of the contact portion 8 also have a plurality of fine recesses and protrusions, so that the semiconductor wafer can be easily detached from the edge film after the substrate is polished. 7.

In the above embodiments, the fluid channels 32, 33, 34, 35 and 36 are provided as separate channels. These fluid channels may be combined with each other, or the pressure chambers may communicate with each other according to the magnitude of the pressure applied to the semiconductor wafer W and the location where the pressure is applied. The above-mentioned embodiments can be appropriately combined with each other.

In the above-described embodiments, the polishing surface is constituted by the polishing pad. However, polished surfaces are not limited to this structure. For example, the polishing surface may consist of a fixed abrasive. The fixed abrasive forms a flat plate containing abrasive grains fixed by a binder. With the fixed abrasive, the polishing process is performed by abrasive grains generated from the fixed abrasive itself. Fixed abrasives include abrasive grains, binder and pores. For example, cerium oxide (CeO ₂ ) having an average particle diameter of 0.5 μm or less is used as abrasive grains, and epoxy resin is used as a binder. This fixed abrasive constitutes a harder polishing surface. The fixed abrasive includes a fixed abrasive pad having a double-layer structure consisting of a thin fixed abrasive layer and an elastic polishing pad attached to the lower surface of the fixed abrasive thin layer. IC-1000 as described above can be used on another hard polished surface.

A substrate holding device according to a tenth embodiment of the present invention will be described below with reference to FIGS. 12A-14 . 12A is a cross-sectional view of a part of a substrate holding device according to a tenth embodiment of the present invention, and FIG. 12B shows a part of the substrate holding device viewed in the direction indicated by arrow A in FIG. 12A. Fig. 13 shows a part of the intermediate membrane viewed in the direction indicated by arrow B in Fig. 12A. Fig. 14 is a perspective view of an air bag incorporated in a substrate holding device according to a tenth embodiment of the present invention. The structure and operation details of the substrate holding device according to the tenth embodiment of the present invention are the same as those of the substrate holding device according to the first embodiment of the present invention, and will not be described below.

The intermediate bladder 200 includes an intermediate film 201 having an intermediate contact portion 202 in contact with the semiconductor wafer W. As shown in FIG. The intermediate film 201 functions as an elastic member and corresponds to the elastic film 91 in the first embodiment. The intermediate contact portion 202 has an outer intermediate contact portion 202a and an inner intermediate contact portion 202b. The outer intermediate contact portion 202a is located radially outward of the inner intermediate contact portion 202b. The outer intermediate contact portion 202a and the inner intermediate contact portion 202b have nose portions 205a, 205b extending upwardly from the pressure chamber 23 and base portions 206a, 206b located within the pressure chamber 23, respectively. Hereinafter, the outer intermediate contact portion 202 a and the inner intermediate contact portion 202 b may be collectively referred to as an intermediate contact portion 202 . The noses 205a, 205b correspond to the flange 91a in the first embodiment.

The intermediate membrane 201 has extensions 203a, 203b connected to the noses 205a, 205b and extending substantially parallel to the intermediate contact portion 202 . The intermediate film 201 also has connection portions 204 a , 204 b extending upward from ends of the extension portions 203 a , 203 b and connected to the chuck 6 through the airbag holder 92 . The pressure chamber 23 is defined by the intermediate film 201 , the airbag holder 92 and the semiconductor wafer W. As shown in FIG.

As shown in FIGS. 13 and 14, the noses 205a, 205b have a plurality of arc-shaped cutouts 210 formed at circumferentially equidistant distances on the peripheral edge of the noses 205a, 205b, each arcuate cutout serving as a detachment-promoting portion. As shown in FIG. 13 , cutouts 210 are formed in corresponding regions 202c of the intermediate contact portion 202 . The regions 202c are arranged equidistantly along the circumferential direction of the intermediate contact portion 202 . Each region 202 c is made of a material having lower adhesion to the semiconductor wafer W than to other regions of the intermediate contact portion 202 . The surface of the region 202c to be in contact with the semiconductor wafer W is roughened by grinding or shot blasting to form fine recesses and protrusions thereon. The entire lower surface of the intermediate contact portion 202 may be roughened. The roughening process is a process of forming fine dimples and protrusions on the surface of the workpiece.

The noses 205a, 205b have upwardly concave grooves 225 formed in their circumferential edges, each groove serving as a disengagement promoting portion. As shown in FIG. 12B , a gap 226 is formed between the groove 225 and the semiconductor wafer W. As shown in FIG. When pressurized fluid is input into the pressure chambers 23, 24 and 25 (see FIG. 2), the groove 225 is deformed to come into close contact with the upper surface of the semiconductor wafer W, thereby sealing the pressure chamber 23 hermetically. At this time, the gap 226 is not formed. The groove 225 is out of contact with the upper surface of the semiconductor wafer W when the pressure inside the pressure chambers 23, 24, and 25 drops to, for example, atmospheric pressure. The groove 225 is preferably formed at a location where the lower portion of the chuck 6 can be brought into contact with the groove 225 when the chuck 6 moves downward. At such a location, the groove 225 is pressed down against the semiconductor wafer W by the chuck 6, so that the inside of the pressure chamber 23 is sealed. In this embodiment, grooves 225 are respectively formed in the cutouts 210 as shown in FIG. 14 , but the positions of the grooves 225 are not limited to the positions of the cutouts 210 .

Next, the operation of releasing the semiconductor wafer by the top ring, that is, the substrate holding device having the above-mentioned structure will be described with reference to FIG. 2 . After the polishing process is completed, the supply of pressurized fluid to the pressure chambers 22, 23, 24, and 25 is stopped, and the pressure of the pressure chambers 22, 23, 24, and 25 is reduced to atmospheric pressure. Then, pressurized fluid is input into the pressure chamber 21 to move the chuck 6 downward so that the contact portion 8 (see FIG. 4 ) and the intermediate contact portion 202 (see FIG. 12A ) come into uniform close contact with the upper surface of the semiconductor wafer W. . In this state, a negative pressure is generated in the pressure chamber 23 or the pressure chamber 24 to adsorb the semiconductor wafer W to the lower end of the top ring 1 under vacuum.

Afterwards, the top ring 1 is moved horizontally to a hanging position where the top ring 1 hangs on the polishing table 100 (see FIG. 1 ), and then negative pressure is generated in the pressure chamber 21 to move the chuck 6 upward. A negative pressure can be generated in the pressure chamber 21 when the top ring 1 is moved towards the hanging position. Thereafter, the top ring 1 moves upwards to a position above the pusher, that is, the substrate lifting device, that is, the transfer position. Then, the vacuum suction force applied to the semiconductor wafer W by the pressure chamber 23 or 24 is stopped.

Subsequently, a fluid (such as a pressurized fluid or a mixture of nitrogen and pure water) is sprayed from the fluid channel 35 or the fluid channel 34 to the semiconductor wafer W. Specifically, when the diameter of the semiconductor wafer W is 300 mm, the fluid is ejected from the fluid channel 35 . Fluid is ejected from the fluid channel 34 when the diameter of the semiconductor wafer W is 200 mm. When the fluid is sprayed onto the semiconductor wafer W, the cutouts 210 and the grooves 225 of the intermediate contact portion 202 start to detach from the semiconductor wafer W, whereby the ambient gas flows into the pressure chamber 23 . Therefore, the sealed state of the pressure chamber 23 made by the intermediate contact portion 202 is broken, so that the semiconductor wafer W can be released from the intermediate airbag 200 smoothly and quickly. The cutouts 210 formed in the middle contact portion 202 are effective to allow the middle contact portion 202 , especially the noses 205a, 205b to come out of contact with the semiconductor wafer W easily. Therefore, the semiconductor wafer W can be quickly released from the intermediate bladder 200 . In this embodiment, the intermediate contact portion 202 has a region 202c having a smaller radial width than the other regions, thereby providing the cutout 210 .

In this embodiment, as described above, the intermediate contact portion 202 is partially made of a material having low adhesion to the semiconductor wafer W, and the intermediate contact portion 202 is partially roughened to form fine grains on the lower surface thereof. Dimples and bumps. With this structure, the semiconductor wafer W can be released from the intermediate air bag 200 smoothly. Preferably, a fluid such as pure water is supplied between the semiconductor wafer W and the intermediate contact portion 202 while the fluid is ejected from the fluid channel 35 or the fluid channel 34 . With this structure, the semiconductor wafer W can be released from the intermediate air bag 200 more smoothly.

A substrate holding device according to an eleventh embodiment of the present invention will be described below with reference to FIG. 15 . Fig. 15 is a rear view of an elastic member of a substrate holding device according to an eleventh embodiment of the present invention. The structure and operation details of the substrate holding device according to the eleventh embodiment of the present invention are the same as those of the substrate holding devices according to the first and tenth embodiments of the present invention, and will not be described below.

As shown in FIG. 15 , the elastic member includes an edge film 7 located in the farthest peripheral region and an intermediate film 201 located radially inward of the edge film 7 . The inner contact portion 8b of the edge film 7 has a cutout 210 formed in its inner peripheral edge. The nose portion 205a of the outer middle contact portion 202a and the nose portion 205b of the inner middle contact portion 202b have cutouts 210 formed in their circumferential edges, respectively. With this structure, the edge film 7 and the intermediate film 201 can be quickly detached from the semiconductor wafer W when fluid is supplied from the fluid channel 35 or the fluid channel 34 (see FIG. 2 ). As described above, when the diameter of the semiconductor wafer W is 300 mm, the fluid is ejected from the fluid channel 35 , and when the diameter of the semiconductor wafer W is 200 mm, the liquid is ejected from the fluid channel 34 . Fluid such as pure water is preferably supplied between the semiconductor wafer W and the contact portion 8 and between the semiconductor wafer W and the intermediate contact portion 202 while the liquid is ejected from the fluid channel 35 or the fluid channel 34 .

A substrate holding device according to a twelfth embodiment of the present invention will be described below with reference to FIGS. 16-19. Fig. 16 is a rear view of a first example of an elastic member incorporated in a substrate holding device according to a twelfth embodiment of the present invention. Fig. 17 is a rear view of a second example of an elastic member incorporated in a substrate holding device according to a twelfth embodiment of the present invention. Fig. 18 is a rear view of a third example of an elastic member incorporated in a substrate holding device according to a twelfth embodiment of the present invention. Fig. 19 is a rear view of a fourth example of an elastic member incorporated in a substrate holding device according to a twelfth embodiment of the present invention. The structure and operation details of the substrate holding device according to the twelfth embodiment of the present invention are the same as those of the substrate holding devices according to the first and tenth embodiments of the present invention, and will not be described below.

As shown in FIGS. 16-19 , the elastic member includes an edge film 7 located at the farthest circumferential region and an intermediate film 201 located radially inside of the edge film 7 . In the first example of the present embodiment shown in FIG. 16, the contact portion 8 of the edge film 7 and the intermediate contact portion 202 of the intermediate film 201 are connected to each other through a plurality of interconnecting portions 220 each serving as a detachment promoting portion. In particular, the inner contact portion 8b of the contact portion 8 and the nose portion 205a of the outer contact portion 202a are interconnected by the interconnection portion 220 . The interconnection portions 220 extend radially from the peripheral edge of the nose portion 205a and are arranged equidistantly along the peripheral direction of the nose portion 205a.

In a second example of this embodiment shown in FIG. 17 , the inner contact portion 8 b and the nose portion 205 a of the outer intermediate contact portion 202 a are integrally connected to each other by an annular interconnection portion 220 . With this structure, the inner contact portion 8b, the outer intermediate contact portion 202a and the interconnection portion 220 are integrally formed as a single annular member.

In a third example of this embodiment shown in FIG. 18 , the inner contact portion 8 b and the nose portion 205 a are connected to each other by a plurality of radial interconnecting portions 220 . Joint portions between the interconnection portion 220 and the inner contact portion and joint portions between the interconnection portion 220 and the nose portion 205a respectively have rounded corners 230 for preventing stress concentration on these joint portions.

In the fourth example of this embodiment shown in FIG. 19, the inner contact portion 8b and the nose portion 205a are connected to each other by a plurality of interconnecting portions 220 extending obliquely to the radial direction.

With the configuration shown in FIGS. 16-19 , stretching of the nose portion 205a is limited by the interconnecting portion 220 . Therefore, it is possible to prevent the nose portion 205a from being stretched when the semiconductor wafer W moves downward after detachment. Therefore, when the fluid is ejected from the fluid passage 35 or the fluid passage 34, the semiconductor wafer W can be quickly detached from the elastic members, that is, the edge film 7 and the intermediate film 201. When the diameter of the semiconductor wafer W is 300 mm, the fluid is ejected from the fluid channel 35 , and when the diameter of the semiconductor wafer W is 200 mm, the liquid is ejected from the fluid channel 34 . Preferably, a fluid such as pure water is provided between the semiconductor wafer W and the contact portion 8 and between the semiconductor wafer W and the intermediate contact portion 202 . The reason why the circumferential edges of the inner contact portion 8b and the nose 205a are interconnected by the interconnection portion 220 is that experiments have shown that the nose 205a of the outer intermediate contact portion 202a must be least prone to detachment from the semiconductor wafer W.

Various embodiments of the invention have been described above. However, the present invention is not limited to the above-mentioned embodiments. Various modifications can be made within the scope of the technical concept of the present invention.

According to the present invention, as described above, since the retractable portion extends downward to follow the upward movement of the vertically movable member, ie, the chuck, the contact portion that remains in contact with the substrate can remain unchanged. Therefore, the contact area between the elastic member and the substrate can remain constant, whereby a uniform pressing force can be obtained over the entire surface of the substrate.

Even when the distance between the vertically movable member and the substrate changes due to wear of the snap ring, the telescoping portion is stretched to follow the change in distance. In this way, the contact portion in contact with the substrate can maintain its original shape. Therefore, the substrate can be pressed with uniform pressure over the entire area from the center of the substrate to its peripheral edge. Therefore, a uniform polishing rate or polishing profile can be obtained over the entire surface of the substrate. Furthermore, since the telescoping portion shrinks according to the wear of the snap ring, the worn snap ring can still be used without having to be replaced.

Furthermore, according to the present invention, when the fluid is sprayed toward the upper surface of the substrate, the detachment-promoting portion starts to be removed from the substrate, so that the contact portion is detached from the substrate smoothly. Accordingly, the substrate can be transferred to a substrate lifting device such as a pusher without being damaged by fluid pressure. The substrate can also be smoothly detached from the elastic member regardless of the type of the substrate, particularly the kind of film formed on the backside (upper surface) of the substrate.

A substrate holding device and polishing device according to a thirteenth embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

20 is a cross-sectional view of the overall structure of a polishing apparatus having a substrate holding device according to a thirteenth embodiment of the present invention. The structure and operation details of the substrate holding device and polishing device according to the thirteenth embodiment are the same as those of the substrate holding device and polishing device of the first embodiment of the present invention, and will not be described below.

As shown in FIG. 20 , the fluid passages 332 , 333 , 334 , 335 and 336 run through the top ring drive shaft 11 and are connected to the pressure regulating unit 120 through a rotary joint 421 at the top of the top ring drive shaft 11 .

The top ring 301 serving as a substrate holding device according to the present invention is explained below. Fig. 21 is a vertical cross-sectional view of the top ring 1 according to the thirteenth embodiment.

As shown in FIG. 21 , the top ring body 2 and the snap ring 3 integrally held on the top ring body 2 define a receiving space therein. An annular retaining ring 5 and a disc-shaped chuck 6 serving as a vertically movable member are arranged in the accommodation space. The chuck 6 is vertically movable in a receiving space formed in the top ring body 2 . The vertical direction refers to a direction perpendicular to the polishing surface 101a. The top ring body 2 , the chuck 6 , the seat ring 5 and the pressure piece 13 jointly define a pressure chamber 321 in the top ring body 2 . As shown in FIG. 21 , the pressure chamber 321 communicates with a fluid passage 332 including tubes, connectors, and the like. The pressure chamber 321 is connected to the pressure regulating unit 120 through the regulator R2 on the fluid channel 332 .

An elastic film 307 to be in contact with the semiconductor wafer W is attached to the lower portion of the chuck 6 . The elastic film 307 has an annular contact portion 308 in contact with the entire upper surface of the semiconductor wafer W. As shown in FIG. The elastic membrane 307 also has a plurality of annular peripheral walls extending upward from the contact portion 308 and connected to the chuck 6 . In particular, the peripheral walls include a first peripheral wall 309a, a second peripheral wall 309b, a third peripheral wall 309c and a fourth peripheral wall 309d, which are collectively referred to as peripheral walls 309a-309d. The elastic membrane 307 has a unitary structure as one integral part.

The first peripheral wall 309 a is located at the outer peripheral edge of the contact portion 308 . The second peripheral wall 309b is located radially inside the first peripheral wall 309a and is separated from the first peripheral wall 309a by a predetermined distance. The third peripheral wall 309c is located radially inside the second peripheral wall 309b and is separated from the second peripheral wall 309b by a predetermined distance. The fourth peripheral wall 309d is located radially inside the third peripheral wall 309c and is separated from the third peripheral wall 309c by a predetermined distance. The first peripheral wall 309a, the second peripheral wall 309b, the third peripheral wall 309c, and the fourth peripheral wall 309d are arranged concentrically with each other.

The first peripheral wall 309 a and the second peripheral wall 309 b have respective upper ends sandwiched between the chuck 6 and the annular edge ring 4 . The third peripheral wall 309c and the fourth peripheral wall 309d have respective upper ends sandwiched between the chuck 6 and the ring clamp 315 . The edge ring 4 and the bracket 315 are held on the chuck 6 by bolts (not shown), so that the elastic film 307 is detachably mounted on the chuck 6 .

Like the pressing sheet 13, the elastic film 307 is made of a strong and durable rubber material such as ethylene propylene diene monomer (EPDM), urethane rubber, silicone rubber. The hardness (Durometer) of the rubber material of the elastic film 307 is preferably 20-60. The elastic film 307 may have a single peripheral wall, or may have a plurality of peripheral walls as in the present embodiment.

Four pressure chambers 322 , 323 , 324 and 325 are defined on the back, ie upper surface, of the elastic membrane 307 . In particular, the contact portion 308 , the first peripheral wall 309 a , the second peripheral wall 309 b and the edge ring 4 define an annular space serving as a pressure chamber 322 . The pressure chamber 322 communicates with a fluid channel 333 containing tubing, connectors, and the like. The pressure chamber 322 is connected to the pressure regulating unit 120 through the regulator R3 on the fluid channel 333 .

The contact portion 308 , the second peripheral wall 309 b , the third peripheral wall 309 c and the chuck 6 define an annular space serving as a pressure chamber 323 . The pressure chamber 323 communicates with a fluid channel 334 containing tubing, connectors, and the like. The pressure chamber 323 is connected to the pressure regulating unit 120 through the regulator R4 on the fluid channel 334 .

The contact portion 308 , the third peripheral wall 309 c , the fourth peripheral wall 309 d and the bracket 315 define an annular space serving as a pressure chamber 324 . The pressure chamber 324 communicates with a fluid channel 335 that includes tubing, connectors, and the like. The pressure chamber 324 is connected to the pressure regulating unit 120 through a regulator R5 on the fluid channel 335 .

The contact portion 308 , the fourth peripheral wall 309 d and the chuck 6 define an annular space serving as a pressure chamber 325 . The pressure chamber 325 communicates with a fluid channel 336 containing tubing, connectors, and the like. The pressure chamber 325 is connected to the pressure regulating unit 120 through a regulator R6 on the fluid passage 336 . The fluid passages 332 , 333 , 334 , 335 and 336 run through the inside of the top ring drive shaft 11 and are respectively connected to the regulators R2 - R6 through the rotary joint 421 .

The pressure chamber 321 defined above the chuck 6 and the pressure chambers 322, 323, 324 and 325 are supplied with a pressurized fluid such as compressed air, or, via fluid passages, 332, 333, 332, 333, 334 , 335 and 336 create atmospheric pressure or vacuum within pressure chambers 321 , 322 , 323 , 324 and 325 . In particular, regulators R2-R6 disposed on fluid passages 332, 333, 334, 335, and 336, respectively, can adjust the pressure of pressurized fluid supplied to corresponding pressure chambers 321, 322, 323, 324, and 325, respectively. Thus, the pressures of the pressure chambers 321, 322, 323, 324, and 325 may be independently controlled, or normal pressure or vacuum may be generated within the pressure chambers 321, 322, 323, 324, and 325 independently.

The pressure in each of the pressure chambers 322, 323, 324, and 325 is independent of the thickness measured by one or more film thickness gauges embedded in the polishing table 100 for measuring the thickness of the film on the polished surface of the semiconductor wafer W. ground control. The film thickness meter may include an optical film thickness meter using light interference or light reflection, or an eddy current type film thickness meter. The signal from the film thickness gauge is analyzed according to the radial position of the semiconductor wafer W to control the internal pressure in each of the concentrically arranged pressure chambers 322, 323, 324, and 325.

In this case, the pressurized fluid supplied to the pressure chambers 322, 323, 324, and 325, or the atmosphere supplied to the pressure chambers when atmospheric pressure is generated therein, can be independently temperature controlled. With this structure, the temperature of a workpiece such as a semiconductor wafer can be directly controlled from the backside of the surface to be polished. In particular, when the temperature of each pressure chamber is individually controlled, the speed of the chemical reaction in the chemical polishing process CMP can be controlled.

The temperature in the pressure chambers 322, 323, 324 and 325 is generally controlled according to the signal from the film thickness gauge in the same manner as the internal pressure of each pressure chamber described above.

The snap ring 3 has a vent hole 54 formed therein. The through hole 53 communicates with the exhaust hole 54 and a small gap G formed between the outer peripheral surface (first peripheral wall 309 a ) of the elastic film 307 and the inner peripheral surface of the snap ring 3 .

The elastic film 307 according to this embodiment will be described in detail below with reference to FIGS. 22A and 22B. FIG. 22A shows a part of a top ring according to a thirteenth embodiment of the present invention, and FIG. 22B shows a state where fluid is fed into a pressure chamber. To simplify the drawings, structural elements other than the elastic membrane are only schematically shown in FIGS. 22A and 22B .

As shown in FIG. 22A, the first peripheral wall 309a has a stretchable portion 340a that is stretchable vertically, that is, perpendicular to the polishing surface 101a. The telescoping portion 340a includes a radially inwardly projecting turn-back portion. The telescoping portion 340 a is located substantially in the central area of the first peripheral wall 309 a, where the telescoping portion 340 a has no influence on the contact portion 308 . The second peripheral wall 309b also has a vertically stretchable telescopic portion 340b. The stretchable portion 340b includes a horizontal portion 340b-1 extending radially outward and located near the lower end of the second peripheral wall 309b, and a folded portion 340b-2 protruding upward from the horizontal portion 340b-1. The folded portion 340b-2 is stretchable in a horizontal direction, that is, a direction parallel to the polishing surface 101a.

The third peripheral wall 309c has a telescopic portion 340c that is vertically telescopic. The expandable portion 340c includes a horizontal portion 340c-1 extending radially inward and located near the lower end of the second peripheral wall 309c, and a folded portion 340c-2 protruding upward from the horizontal portion 340c-1. The fourth peripheral wall 309d also has a vertically retractable telescopic portion 340d. The expandable portion 340d includes a horizontal portion 340d-1 extending radially outward and located near the lower end of the fourth peripheral wall 309d, and a folded portion 340d-2 protruding upward from the horizontal portion 340d-1. The folded portion 340c-2 and the folded portion 340d-2 are stretchable in a horizontal direction, that is, a direction parallel to the polishing surface 101a.

Since the peripheral walls 309a, 309b, 309c, and 309d have stretchable portions 340a, 340b, 340c, and 340d, respectively, the peripheral walls 309a, 309b, 309c, and 309d are stretchable while the contact portion 308 remains unchanged. In particular, the peripheral walls 309a, 309b, 309c, and 309d including the corresponding stretchable portions 340a, 340b, 340c, and 340d may be uniformly stretched in the vertical direction. Therefore, as shown in FIG. 22B, when pressurized fluid is input into the pressure chambers 322, 323, 324, and 325 to lift the chuck 6 (see FIG. 21), the telescoping portions 340a, 340b, 340c, and 340d expand to follow the chuck 6. Upward movement of disc 6. Therefore, the contact area between the elastic film 307 (contact portion 308 ) and the semiconductor wafer W can remain unchanged.

Next, the operation of the top ring 301 having the above-mentioned structure will be described in detail.

In the polishing apparatus having the above structure, when the semiconductor wafer W is carried into the polishing apparatus, the top ring 301 is entirely moved to the transfer position where the semiconductor wafer W is transferred. In the case where the diameter of the semiconductor wafer W is 200 mm, the pressure adjustment unit 120 communicates with the pressure chamber 323 through the fluid passage 334 . On the other hand, in the case where the diameter of the semiconductor wafer W is 300 mm, the pressure adjustment unit 120 communicates with the pressure chamber 324 through the fluid passage 335 .

The contact portion 308 constituting the pressure chamber 323 and the pressure chamber 324 has holes and grooves (not shown), respectively, through which the semiconductor W can be directly attracted and held by the lower end of the top ring 301 .

After the semiconductor wafer W is sucked onto the top ring 301, the top ring is entirely moved to a position above the polishing table 100 having the polishing surface 101a. The outer peripheral edge of the semiconductor wafer W is held by the snap ring 3, whereby the semiconductor wafer W does not come off the top ring 301, or the semiconductor wafer W does not slip.

After that, the attractive force of the semiconductor wafer W is released. At about the same time, the top ring cylinder 111 connected to the top ring drive shaft 11 is activated to press the snap ring 3 held at the lower end of the top ring 301 against the polishing surface 101a of the polishing table 100 with a predetermined pressure. Then, pressurized fluid is supplied to the pressure chamber 321 to move the chuck 6 downward so that the contact portion 308 of the elastic film 307 comes into contact with the semiconductor wafer W. Next, pressurized fluids having respective different pressures are input into the pressure chambers 322 , 323 , 324 and 325 , so that the chuck is moved upward while the semiconductor wafer W is pressed against the polishing surface 101 a of the polishing table 100 . At this time, the stretchable portions 340a, 340b, 340c, and 340d on the edge film 7 are stretched to follow the upward movement of the chuck 6 . Therefore, the contact area between the lower surface (contact portion 308 ) of the elastic film 307 and the semiconductor wafer W can remain unchanged. Then, while the polishing liquid Q is supplied from the polishing liquid supply nozzle 102 onto the polishing surface 101a, the top ring 301 and the polishing table 100 rotate independently of each other. The polishing liquid Q is held on the polishing surface 101 a of the polishing pad 101 , and the semiconductor wafer W is polished with the polishing liquid Q between its (lower) surface to be polished and the polishing pad 101 .

In this embodiment, the pressure chambers 322, 323, 324, and 325 can be sufficiently inflated even if the pressure of the pressurized fluid is small. Therefore, the semiconductor wafer W can be pressed with a small pressure. When a semiconductor wafer having a low-k material having a low dielectric constant and a low hardness.

With the above structure, since the polishing of the semiconductor wafer W is performed with the snap ring 3 in sliding contact with the polishing surface 101a, the snap ring 3 wears over time. Therefore, the distance between the lower surface of the chuck 6 and the semiconductor wafer W becomes smaller. In a conventional substrate holding device, when the distance between the chuck and the semiconductor wafer becomes smaller, the contact area between the elastic film and the semiconductor wafer changes, resulting in a change in the polishing profile. According to the present embodiment, even in this case, the stretchable portions 340a, 340b, 340c, and 340d will contract upward as the snap ring 3 wears, thereby making the contact between the semiconductor wafer W and the elastic film 307 (contact portion 308) The contact area can remain the same. Therefore, changes in the polishing profile can be prevented.

Although an integrally formed elastic film is used in this embodiment, the present invention is not limited to such an elastic film. It is also possible to use an elastic membrane having a plurality of partitions separated by circumferentially extending slits formed in the contact portion. In this case, the contact area between the semiconductor wafer and the elastic film 307 (contact portion 308) can also be kept constant by providing the stretchable portion described above. Therefore, a uniform polishing rate can be obtained over the entire polishing surface of the semiconductor wafer W.

Localized regions of the semiconductor wafer W below the pressure chambers 322, 323, 324, and 325 are pressed against the polishing surface of the polishing pad 101 under the pressure of the pressurized fluid supplied to the pressure chambers 322, 323, 324, and 325. 101a on. Therefore, the pressures of the pressurized fluids supplied to the pressure chambers 322, 323, 324, and 325 are controlled independently of each other, so that the entire surface of the semiconductor wafer W can be pressed against the polishing pad 101 with a uniform pressing force. In this way, a uniform polishing rate can be obtained over the entire surface of the semiconductor wafer W. Likewise, regulator R2 adjusts the pressure of the pressurized fluid supplied to pressure chamber 321 to vary the pressure applied to polishing pad 101 by snap ring 3 . In this way, the pressure applied to the polishing pad 101 by the snap ring 3 and the pressure applied by the respective pressure chambers 322, 323, 324, and 325 to press the semiconductor wafer W against the polishing pad 101 are properly adjusted during polishing. , to control the polishing profile of the semiconductor wafer W.

As described above, the pressure applied by the top ring cylinder 111 to press the snap ring 3 against the polishing pad 101 and the pressure applied by the pressurized fluid input into each of the pressure chambers 322, 323, 324, and 325 are used to hold the semiconductor The pressure with which the wafer W is pressed against the polishing pad 101 is properly adjusted to polish the semiconductor wafer W. As shown in FIG. When the polishing of the semiconductor wafer W is completed, the supply of pressurized fluid to the pressure chambers 322, 323, 324, and 325 is stopped, and the pressure inside the pressure chambers 322, 323, 324, and 325 is reduced to atmospheric pressure. Then, pressurized fluid is supplied to the pressure chamber 321 to move the chuck 6 downward so that the contact portion 308 comes into close contact with the upper surface of the semiconductor wafer W uniformly. In this state, the semiconductor wafer W is attracted to the lower end of the top ring 301 again under vacuum. Immediately thereafter, atmospheric or negative pressure is generated in the pressure chamber 321 . This is because, if the pressure chamber 321 is kept at a high pressure, the semiconductor wafer W is partially pressed against the polishing surface 101 a by the lower surface of the chuck 6 .

After the semiconductor wafer W is adsorbed in the above-mentioned manner, the top ring 301 moves as a whole to the transfer position where the semiconductor wafer W is transferred, and stops passing through holes or grooves formed in the lower part of the pressure chamber 323 or in the pressure chamber 324. (not shown) vacuum attraction. Then, pressurized fluid having a predetermined pressure is input into the pressure chambers 322, 323, 324, and 325, wherein the pressurized fluid is sprayed onto the semiconductor wafer W through the above-mentioned holes or grooves, thereby releasing the semiconductor wafer W.

The polishing liquid Q for polishing the semiconductor wafer W tends to flow into the small gap G between the outer peripheral surface of the elastic film 307 and the snap ring 3 . If the polishing liquid Q is firmly deposited on the outer circumferential surface of the elastic membrane 307 and the snap ring 3, it will hinder the vertical smoothness of the bracket ring 5, the chuck 6, the elastic membrane 307, etc. relative to the top ring body 2 and the snap ring 3. move. In order to avoid this disadvantage, a cleaning liquid, such as pure water, is fed into the annular cleaning liquid channel 51 through the fluid channel 30 . In this way, the cleaning liquid is input into the space above the gap G through the plurality of communication holes 53, thereby washing the polishing liquid Q in the gap G to prevent the polishing liquid Q from being firmly deposited in the gap G. Preferably, the cleaning liquid is provided after the polished semiconductor wafer W is detached and until the next semiconductor wafer to be polished is sucked onto the top ring 301 .

A top ring serving as a substrate holding device according to a fourteenth embodiment of the present invention will be described below with reference to FIGS. 23A and 23B . FIG. 23A shows a part of a top ring according to a fourteenth embodiment of the present invention, and FIG. 22B shows a state where fluid is fed into a pressure chamber. To simplify the drawings, structural details other than the elastic membrane are shown schematically in Figures 23A and 23B. The structure and operation details of the substrate holding device according to the fourteenth embodiment of the present invention are the same as those of the substrate holding device according to the thirteenth embodiment of the present invention, and will not be described below.

As shown in FIG. 23A, the second peripheral wall 309b has a telescopic portion 342b that is vertically telescopic. The telescoping portion 342b includes two folded portions 342b-1, 342b-2 located near the lower end of the second peripheral wall 309b. The folded portion 342b-1 protrudes radially inward, while the folded portion 342b-2 protrudes radially outward. The third peripheral wall 309c and the fourth peripheral wall 309d also respectively have telescopic portions 342c, 342d that can be vertically telescopic. The telescoping portion 342c includes two folded portions 342c-1, 342c-2 located near the lower end of the third peripheral wall 309c. The folded portion 342c-1 protrudes radially outward, while the folded portion 342c-2 protrudes radially inward. The telescoping portion 342d includes two folded portions 342d-1, 342d-2 located near the lower end of the fourth peripheral wall 309d. The folded portion 342d-1 protrudes radially inward, while the folded portion 342d-2 protrudes radially outward.

Since the peripheral walls 309a, 309b, 309c, and 309d have stretchable portions 340a, 342b, 342c, and 342d, respectively, the peripheral walls 309a, 309b, 309c, and 309d are stretchable while the contact portion 308 remains unchanged. In particular, the peripheral walls 309a, 309b, 309c, and 309d including the corresponding stretchable portions 340a, 342b, 342c, and 342d may be uniformly stretched in the vertical direction. Thus, as shown in FIG. 23B, when pressurized fluid is input into the pressure chambers 322, 323, 324, and 325 to move the chuck 6 upward (see FIG. 21), the telescoping portions 340a, 340b, 340c, and 342d expand to follow Upward movement of chuck 6. Therefore, the contact area between the elastic film 307 (contact portion 308 ) and the semiconductor wafer W can remain unchanged.

A top ring serving as a substrate holding device according to a fifteenth embodiment of the present invention will be described below with reference to FIGS. 24A and 24B . FIG. 24A shows a part of a top ring according to a fifteenth embodiment of the present invention, and FIG. 24B shows a state where fluid is fed into a pressure chamber. To simplify the drawings, structural details other than the elastic membrane are shown schematically in Figures 24A and 24B. The structure and operation details of the substrate holding device according to the fifteenth embodiment of the present invention are the same as those of the substrate holding device according to the thirteenth embodiment of the present invention, and will not be described below.

As shown in FIG. 24A, the second peripheral wall 309b has a stretchable portion 343b that can stretch vertically. The telescopic portion 343b includes a horizontal portion 343b-1 extending radially outward and located near the lower end of the second peripheral wall 309b, and a turn-back portion 343b-1 integrally connected to the inner end of the horizontal portion 343b-1 and protruding radially inward. 2. The third peripheral wall 309c and the fourth peripheral wall 309d also respectively have telescopic portions 343c, 342d that can be vertically telescopic. The telescopic portion 343c includes a horizontal portion 343c-1 extending radially outward and located near the lower end of the third peripheral wall 309c, and a turn-back portion 343c-1 integrally connected to the outer end of the horizontal portion 343c-1 and protruding radially outward. 2. The telescopic portion 343d includes a horizontal portion 343d-1 extending radially outward and located near the lower end of the fourth peripheral wall 309d, and a turn-back portion 343d integrally connected to the inner end of the horizontal portion 343d-1 and protruding radially inward. -2.

Since the peripheral walls 309a, 309b, 309c, and 309d have stretchable portions 340a, 343b, 343c, and 343d, respectively, the peripheral walls 309a, 309b, 309c, and 309d are stretchable while the contact portion 308 remains unchanged. In particular, the peripheral walls 309a, 309b, 309c, and 309d including the corresponding stretchable portions 340a, 343b, 343c, and 343d may be uniformly stretched in the vertical direction. Thus, as shown in FIG. 24B, when pressurized fluid is input into the pressure chambers 322, 323, 324, and 325 to move the chuck 6 upward (see FIG. 21), the telescoping portions 340a, 343b, 343c, and 343d expand to follow Upward movement of chuck 6. Therefore, the contact area between the elastic film 307 (contact portion 308 ) and the semiconductor wafer W can remain unchanged.

A top ring serving as a substrate holding device according to a sixteenth embodiment of the present invention will be described below with reference to FIGS. 25A and 25B . FIG. 25A shows a part of a top ring according to a sixteenth embodiment of the present invention, and FIG. 25B shows a state where fluid is fed into a pressure chamber. To simplify the drawings, structural details other than the elastic membrane are shown schematically in FIGS. 25A and 25B . The structure and operation details of the substrate holding device according to the sixteenth embodiment of the present invention are the same as those of the substrate holding device according to the thirteenth embodiment of the present invention, and will not be described below.

As shown in FIG. 25A, the second peripheral wall 309b has a stretchable portion 344b that can stretch vertically. The telescopic portion 344b includes a folded portion protruding radially outward and located substantially in the central region of the second peripheral wall 309b. The third peripheral wall 309c and the fourth peripheral wall 309d also respectively have telescopic portions 344c, 344d that can be vertically telescopic. The telescoping portion 344c includes a folded portion protruding radially inward and located substantially in the central region of the third peripheral wall 309c. The telescoping portion 344d includes a folded portion protruding radially outward and located substantially in the central region of the fourth peripheral wall 309d. Since the peripheral walls 309a, 309b, 309c, and 309d have stretchable portions 340a, 344b, 344c, and 344d, respectively, the peripheral walls 309a, 309b, 309c, and 309d are stretchable while the contact portion 308 remains unchanged. In particular, the peripheral walls 309a, 309b, 309c, and 309d including the corresponding stretchable portions 340a, 344b, 344c, and 344d may be uniformly stretched in the vertical direction. Thus, as shown in FIG. 25B, when pressurized fluid is input into the pressure chambers 322, 323, 324, and 325 to move the chuck 6 upward (see FIG. 21), the telescoping portions 340a, 344b, 344c, and 344d expand to follow Upward movement of chuck 6. Therefore, the contact area between the elastic film 307 (contact portion 308 ) and the semiconductor wafer W can remain unchanged.

A top ring serving as a substrate holding device according to a seventeenth embodiment of the present invention will be described below with reference to FIGS. 26A and 26B . Fig. 26A shows a part of a top ring according to a seventeenth embodiment of the present invention, and Fig. 26B shows a state where fluid is fed into a pressure chamber. To simplify the drawings, structural details other than the elastic membrane are shown schematically in FIGS. 26A and 26B . The structure and operation details of the substrate holding device according to the seventeenth embodiment of the present invention are the same as those of the substrate holding device according to the thirteenth embodiment of the present invention, and will not be described below.

As shown in FIG. 26A, the second peripheral wall 309b has a telescopic portion 345b that is vertically telescopic. The retractable portion 345b includes a horizontal portion 345b-1 extending radially outward near the lower end of the second peripheral wall 309b and a folded portion 345b-2 protruding inward substantially at the central region of the second peripheral wall 309b. The third peripheral wall 309c and the fourth peripheral wall 309d also respectively have telescopic portions 345c, 345d that can be vertically telescopic. The expandable portion 345c includes a horizontal portion 345c-1 extending radially inward near the lower end of the third peripheral wall 309c, and a folded portion 345c-2 protruding radially outward substantially in the central region of the third peripheral wall 309c. The expandable portion 345d includes a horizontal portion 345d-1 extending radially outward near the lower end of the fourth peripheral wall 309d, and a folded portion 345d-2 protruding radially inward substantially at the central region of the fourth peripheral wall 309d.

Since the peripheral walls 309a, 309b, 309c, and 309d have stretchable portions 340a, 345b, 345c, and 345d, respectively, the peripheral walls 309a, 309b, 309c, and 309d are stretchable while the contact portion 308 remains unchanged. In particular, the peripheral walls 309a, 309b, 309c, and 309d including the corresponding stretchable portions 340a, 345b, 345c, and 345d may be uniformly stretched in the vertical direction. Thus, as shown in FIG. 26B, when pressurized fluid is input into the pressure chambers 322, 323, 324, and 325 to move the chuck 6 upward (see FIG. 21), the telescoping portions 340a, 345b, 345c, and 345d expand to follow Upward movement of chuck 6. Therefore, the contact area between the elastic film 307 (contact portion 308 ) and the semiconductor wafer W can remain unchanged.

A top ring serving as a substrate holding device according to an eighteenth embodiment of the present invention will be described below with reference to FIGS. 27A-27C . 27A is an enlarged fragmentary sectional view of a portion of a first example of a top ring according to an eighteenth embodiment of the present invention, and FIG. 27B is an enlarged partial view of a portion of a second example of a top ring according to an eighteenth embodiment of the present invention Cross-sectional view, Figure 27C is an enlarged fragmentary cross-sectional view of a portion of a third example of a top ring according to an eighteenth embodiment of the present invention. The structure and operation details of the substrate holding device according to the eighteenth embodiment of the present invention are the same as those of the substrate holding device according to the thirteenth embodiment of the present invention, and will not be described below.

As shown in FIG. 27A, at the outer peripheral edge of the contact portion 308 of the elastic film 307, an upwardly inclined inclined portion 308a is formed. The inclined portion 308a has a curved cross section. With this structure, even if the pressurized fluid is supplied to the pressure chambers 322, 323 to lift the chuck 6, the contact portion 308 of the elastic film 307 and the outer peripheral edge of the semiconductor wafer W can not be in contact with each other. Therefore, the elastic film 307 does not apply pressure to the outer peripheral edge of the semiconductor wafer W. As shown in FIG. In this way, so-called "corner rounding" in which the outer peripheral edge of the semiconductor wafer W is excessively polished can be prevented from occurring.

Preferably, the gap between the inclined portion 308a and the semiconductor wafer W should be as small as possible, because the polishing liquid tends to stay in this gap. Therefore, preferably, the vertical dimension of the inclined portion 308a is smaller than its horizontal dimension. In this embodiment, the second peripheral wall 309b has a stretchable portion 346b. The telescoping portion 346b includes a horizontal portion extending radially outward and located near the lower end of the second peripheral wall 309b. The second peripheral wall 309b may also have a folded portion as shown in the thirteenth to seventeenth embodiments.

The second example shown in FIG. 27B is different from the first example shown in FIG. 27A in the position of the second peripheral wall 309b. In particular, the lower end of the second peripheral wall 309b abuts against the first peripheral wall 309a, and the inclined portion 308a extends upward from the lower end of the second peripheral wall 309b. Therefore, the pressure inside the pressure chamber 323 can be applied to a region of the semiconductor wafer W located radially inward of the outer circumferential edge of the semiconductor wafer W. As shown in FIG.

The third example shown in FIG. 27C is different from the first example shown in FIG. 27A in the thickness of the inclined portion 308a. In particular, in the third example, the inclined portion 308 a is thinner than the horizontal portion of the contact portion 308 . Therefore, when pressurized fluid is supplied to the pressure chamber 322, the inclined portion 308a can be easily expanded to press only the outer peripheral edge of the semiconductor wafer W against the polishing surface 101a (see FIG. 1) under a desired pressure. . In this way, the polishing rate at the outer peripheral edge of the semiconductor wafer W can be independently controlled.

A top ring serving as a substrate holding device according to a nineteenth embodiment of the present invention will be described below with reference to FIGS. 28A-28C . 28A is an enlarged fragmentary sectional view of a portion of a first example of a top ring according to a nineteenth embodiment of the present invention, and FIG. 28B is an enlarged partial view of a portion of a second example of a top ring according to a nineteenth embodiment of the present invention Cross-sectional view, Figure 28C is an enlarged fragmentary cross-sectional view of a portion of a third example of a top ring according to a nineteenth embodiment of the present invention. The structural details and preferences of the substrate holding device according to the nineteenth embodiment of the present invention are the same as those of the substrate holding devices according to the thirteenth and eighteenth embodiments of the present invention, and will not be described below.

As shown in FIG. 28A, in the outer peripheral edge of the contact portion 308 of the elastic film 307, an upwardly inclined inclined portion 308b is formed. The inclined portion 308b has a straight cross section. With this structure, even if the pressurized fluid is supplied to the pressure chambers 322, 323 to lift the chuck 6, the contact portion 308 of the elastic film 307 and the outer peripheral edge of the semiconductor wafer W can not be in contact with each other. To reduce the gap between the inclined portion 308b and the semiconductor wafer W, preferably, the vertical dimension of the inclined portion 308b is smaller than its horizontal dimension.

The lower end of the second peripheral wall 309b shown in FIG. 28B abuts against the first peripheral wall 309a. The inclined portion 308b extends upward from the lower end of the second peripheral wall 309b. Therefore, the pressure generated in the pressure chamber 323 can be applied to a region of the semiconductor wafer W located radially inward of the outer peripheral edge of the semiconductor wafer W. As shown in FIG.

In the third example shown in FIG. 28C , the inclined portion 308 b is thinner than the horizontal portion of the contact portion 308 . Therefore, when pressurized fluid is supplied to the pressure chamber 322, the inclined portion 308b can easily expand to press only the outer peripheral edge of the semiconductor wafer W against the polishing surface 101a (see FIG. 1 ) under a desired pressure. . In this way, the polishing rate at the outer peripheral edge of the semiconductor wafer W can be independently controlled.

During the polishing process, the lower end of the snap ring 3 is gradually worn due to sliding contact with the polishing surface 101a. Therefore, the distance between the chuck 6 and the semiconductor wafer W becomes smaller, whereby the contact area between the elastic film 307 and the semiconductor wafer W is changed. Therefore, the polishing rate tends to be changed locally. In order to avoid this kind of problem, preferably, the stretchable parts 340a-340d, 341b-341d, 342b-342d, 343b-343d, 344b-344d, 345b-345d, 346b can be extended to an extent greater than the amount of wear of the snap ring 3. telescopic. Thereby, the stretchable portion can be contracted upward when the snap ring 3 is worn, and thus the polishing rate can be prevented from being locally changed.

According to the present invention, as described above, since the stretchable portion extends perpendicularly to the polishing surface when the fluid is supplied to the pressure chamber, the shape of the contact portion of the elastic film can be kept unchanged. Therefore, the contact area between the elastic film (contact portion) and the substrate can be kept constant, whereby a uniform polishing rate can be obtained over the entire polishing surface of the substrate. The stretchable portion is effective to maintain the elastic membrane and the substrate in sufficient contact with each other. Therefore, an elastic film with high hardness can be used, thereby allowing the durability of the elastic film to be improved. In this case, the high-hardness elastic film can maintain the contact area between the substrate and the elastic film (contact portion) as compared with the low-hardness elastic film. Thereby, a stable polishing rate can be obtained.

Industrial Applicability

The present invention is applicable to a substrate holding device for holding a substrate to be polished and pressing the substrate against a polishing surface, especially for holding a substrate in a polishing device for polishing said substrate to a flat and smooth surface , Substrate holders such as semiconductor wafers. The invention is also applicable to a polishing device having the substrate holding device.

Claims (35)

1. one kind is used for polished substrate kept and is pressed against substrate holding apparatus on the polished surface, and described substrate holding apparatus comprises:

But vertical moving parts; And

But one links to each other to be used to limit the elastomeric element of a chamber with described vertical moving parts;

But described elastomeric element comprises a contact portion that contacts with described substrate and a perisporium that extends upward and link to each other with described vertical moving parts from described contact portion, but described perisporium has the scalable part of a vertical stretching and contraction.

2. substrate holding apparatus according to claim 1 is characterized in that:

Described perisporium comprises a periphery wall and an internal perisporium that is positioned at the radially inner side of described periphery wall;

In described periphery wall and the described internal perisporium at least one has described scalable part; And

The position of described contact portion between described periphery wall and described internal perisporium is separated.

3. substrate holding apparatus according to claim 1 and 2 is characterized in that, described perisporium has a folded part, to form described scalable part.

4. substrate holding apparatus according to claim 3 is characterized in that described folded part has curved substantially cross section.

5. substrate holding apparatus according to claim 1 and 2 is characterized in that, described scalable part is made by the material softer than described contact portion.

6. substrate holding apparatus according to claim 1 and 2 is characterized in that, a predetermined portions of described perisporium is thinner than described contact portion, to form described scalable part.

7. according to any one described substrate holding apparatus among the claim 1-6, it is characterized in that described perisporium has a part of being made by the material harder than described contact portion and being positioned under the described scalable part.

8. according to any one described substrate holding apparatus among the claim 1-6, it is characterized in that described perisporium has one by thicker than described contact portion and be positioned at part under the described scalable part.

9. according to any one described substrate holding apparatus among the claim 1-6, it is characterized in that a hard component harder than described elastomeric element is embedded in the described perisporium, and described hard component is positioned under the described scalable part.

10. according to any one described substrate holding apparatus among the claim 1-6, it is characterized in that a hard component harder than described elastomeric element is fixed on the described perisporium, and described hard component is positioned under the described scalable part.

11., it is characterized in that described perisporium has the part that a surface scribbles the hard material harder than described elastomeric element according to any one described substrate holding apparatus among the claim 1-6, and described part is positioned under the described scalable part.

12. one kind is used for polished substrate kept and is pressed against substrate holding apparatus on the polished surface, described substrate holding apparatus comprises:

But vertical moving parts; And

But one links to each other to limit the elastomeric element of a chamber with described vertical moving parts;

But described elastomeric element comprises a contact portion that contacts with described substrate and a perisporium that extends upward and link to each other with described vertical moving parts from described contact portion, described perisporium comprises a periphery wall and an internal perisporium that is positioned at the radially inner side of described periphery wall, and described contact portion is separated in the position between described periphery wall and described internal perisporium.

13. according to any one described substrate holding apparatus among the claim 1-12, it is characterized in that, thereby comprise that also one contacts with the upper surface of described contact portion described contact portion is pressed against compacting part on the described substrate.

14. substrate holding apparatus according to claim 13 is characterized in that, described compacting part has a plurality of grooves that are formed on its lower surface and radially extend.

15. substrate holding apparatus according to claim 13 is characterized in that, described compacting part has one and is formed on its lower surface to be used for providing to the upper surface of described contact portion the fluid supply port of fluid.

16., it is characterized in that described contact portion has on the surface formed thereon and along the thick portion of the circumferential extension of described contact portion according to any one described substrate holding apparatus among the claim 13-15.

17. substrate holding apparatus according to claim 16 is characterized in that, described thick portion has and is substantially triangular in shape or the cross section of arc.

18., it is characterized in that a reinforcing member is embedded in the described contact portion according to any one described substrate holding apparatus among the claim 13-17.

19., it is characterized in that described contact portion has a plurality of lip-deep projectioies formed thereon and depression according to any one described substrate holding apparatus among the claim 1-18.

20. a burnishing device comprises:

According to any one described substrate holding apparatus among the claim 1-19; And

Polishing block with polished surface.

21. the method for a polished substrate comprises:

By keeping this substrate according to any one described substrate holding apparatus among the claim 1-19;

This substrate is placed on the polished surface of a polishing block;

But move down described vertical moving parts, so that described contact portion is pressed against on this substrate;

When being pressed against described contact portion on this substrate, in described chamber, provide pressure fluid;

Make this substrate and described polished surface sliding contact, to polish this substrate.

22. one kind is used for polished substrate kept and is pressed against substrate holding apparatus on the polished surface, described substrate holding apparatus comprises:

But vertical moving parts; And

An elastomeric element that is used to limit a chamber;

Described elastomeric element has a contact portion that contacts with described substrate, and described contact portion has one and is used to promote that described contact portion promotes part from the disengaging that described substrate breaks away from.

23. substrate holding apparatus according to claim 22 is characterized in that, described disengaging promotes part to comprise an otch on the circumferential edges that is formed at described contact portion.

24., it is characterized in that described contact portion has a zone of being made by the low material of adhesive force of the adhesive force of described substrate being compared described elastomeric element according to claim 22 or 23 described substrate holding apparatus.

25., it is characterized in that a surface of described contact portion has a plurality of projectioies and depression according to any one described substrate holding apparatus among the claim 22-24.

26. substrate holding apparatus according to claim 22, it is characterized in that, described elastomeric element comprises a plurality of contact portions, and described disengaging promotes part to comprise and another interconnective interconnecting parts that is used for making described a plurality of contact portions.

27. substrate holding apparatus according to claim 22 is characterized in that, described disengaging promote part comprise one be formed in the described contact portion to the groove that is recessed on, and

When pressure fluid was imported in the described chamber, described groove closely contacted with described substrate.

28. a burnishing device comprises:

According to any one described substrate holding apparatus among the claim 22-27; And

Polishing block with polished surface.

29. one kind is used for polished substrate kept and is pressed against substrate holding apparatus on the polished surface, described substrate holding apparatus comprises:

The movable member that can move perpendicular to described polished surface; And

One links to each other to be used to limit the elastic membrane of a plurality of chambers with described movable member;

Described elastic membrane comprises a contact portion that contacts with described substrate and a plurality of perisporiums that described contact portion is linked to each other with described movable member of being used for, and each in described a plurality of perisporiums has a scalable part that can stretch and shrink perpendicular to described polished surface.

30. substrate holding apparatus according to claim 29 is characterized in that, described elastic membrane has overall structure.

31., it is characterized in that described contact portion has one and is positioned on its outer rim and acclivitous sloping portion according to claim 29 or 30 described substrate holding apparatus.

32. substrate holding apparatus according to claim 31 is characterized in that, described sloping portion has crooked cross section.

33., it is characterized in that described sloping portion has straight cross section according to claim 22 or 23 described substrate holding apparatus.

34., it is characterized in that described sloping portion is thinner than described contact portion according to any one described substrate holding apparatus among the claim 31-33.

35. a burnishing device comprises:

According to any one described substrate holding apparatus among the claim 29-34; And

Polishing block with polished surface.

Images