JP3354137B2 - Wafer polishing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polishing apparatus,
More specifically, a holder for holding the wafer, and a surface plate having a polished surface for polishing a surface to be polished of the wafer held by the holder, a relative position between the holding portion and the surface plate The present invention relates to a wafer polishing apparatus for polishing a polished surface of a wafer by moving the wafer. For example, there is one used for mirror-polishing a surface to be polished (hereinafter, also referred to as a “wafer surface”) of a wafer for manufacturing semiconductor chips.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of semiconductor devices has increased, there has been a demand for further improvement in flatness and surface quality of a silicon wafer or the like as a base material thereof. In addition, there is an increasing demand for flattening with higher precision in polishing an interlayer insulating film, metal wiring, and the like deposited and formed when a device is formed on the wafer surface. Therefore, a wafer polishing apparatus that can mirror-polish the surface to be polished of the wafer with higher precision is required. 2. Description of the Related Art Conventionally, some wafer polishing apparatuses have an airbag function in a holding unit for holding a wafer so that the entire surface of the wafer surface can be pressed against a polishing surface of a surface plate with a uniform pressure.

An example of a holding unit according to the wafer polishing apparatus will be described below with reference to FIG. As shown in FIG. 9, a polishing pad 51 or the like is adhered to a polishing surface 52 on a surface plate 50 that rotates (rotates) about a vertical axis.
Is formed above, and a holding portion 60 that can rotate (rotate) and move up and down around an axis in the vertical direction is provided. The holding portion 60 has a concave portion 6 that opens downward.
2a, a wafer holding plate 64 having a holding surface for holding the wafer 12, an outer peripheral portion 66b is fixed to an outer peripheral side wall portion 62b of the head member 62, and an inner peripheral portion 66a is formed of the wafer. A plate-like elastic member 66 fixed to the outer peripheral portion 64a of the holding plate 64 and suspending the wafer holding plate 64 in a vertical direction or the like within a minute range, and holding the wafer inside the head member 62; A pressure chamber 65, which is a closed space defined by a board 64 and a plate-shaped elastic member 66, is provided.

[0004] Reference numeral 67 denotes a decompression means for adsorbing a wafer.
The plurality of communication holes 67a opened on the lower surface, which is the holding surface of the wafer holding board 64, communicate with each other via a conduit 67b. The wafer 12 can be suction-held on the holding surface of the wafer holding board 64 by the pressure reducing means 67. Reference numeral 68 denotes a pressurizing unit that supplies a fluid having a predetermined pressure to the pressure chamber 65 and presses the wafer 12 against the polishing surface 52 of the platen 50 via the wafer holding plate 64. Reference numeral 69 denotes a pressure chamber decompression unit that depressurizes the pressure chamber 65. Also, one tapered fitting portion (male type) having a tapered projection gradually reduced in diameter from the inner bottom surface of the head member 62 and a wafer holding plate 64 facing the one tapered fitting portion 70. Provided on the upper surface,
When the pressure chamber 65 is depressurized by the pressure chamber depressurizing means 69, the pressure chamber 65 is sucked and formed into a taper opposite to the one taper fitting part 70 so as to fit into the one taper fitting part 70. And the other tapered fitting portion 72 (female type).

According to this polishing apparatus, the wafer holding plate 6
The surface to be polished (wafer surface 12a) of the wafer held by the suction action on the wafer 4 has a plate-like elastic member 6 made of a rubber plate or the like.
6 can quickly follow the inclination of the polishing surface 52, etc.
Can also press the entire surface 12a of the wafer 12a against the polished surface 52 with a uniform pressure, even in a state following the inclination of the polished surface 52 or the like. Therefore, the wafer surface 12a can be uniformly and suitably mirror-polished. In addition, by fitting one tapered fitting portion 70 (male type) and the other tapered fitting portion 72 (female type), the wafer holding plate 64 can be positioned with high accuracy, and the bonding accuracy of the wafer 12 can be improved. In addition, the polishing accuracy of the wafer can be improved, and it is possible to suitably cope with automation.

[0006]

In the above-described wafer polishing apparatus, the wafer surface 12a is polished by pressing the wafer surface 12a against a polishing surface of a cloth (polishing cloth 51) attached to the surface plate 50 with a predetermined pressing force. Is applied. At this time, the portion of the polishing pad 51 against which the wafer surface 12a is pressed is recessed to form a recess as compared with the portion of the polishing pad 51 where the wafer surface 12a is not pressed, as shown in FIG. The corners of the wafer 12 come into contact with the side wall surfaces of the concave portions and are polished. As described above, when the corners of the wafer 12 are polished by the side wall surface of the concave portion, the polishing surface of the polishing pad 12 is deformed or worn, and the flatness of the polished wafer 12 cannot be ensured. For this reason, the shape of the polished surface 52 of the surface plate deteriorated by the polishing process of the wafer is dressed in a step different from the polishing step. That is, in a dressing step different from the polishing step, a dresser member such as a dummy wafer or a ceramic plate is held on the holding portion 60 by, for example, being attached to a wafer holding plate 64, and the dresser member is transferred to the polishing cloth 51. Is pressed against a polishing surface 52 of a surface plate formed by sticking, thereby dressing deformation and abrasion generated in the polishing cloth 51. Further, in the case of a new polishing cloth 51, the surface state of the polishing cloth is made uniform (seasoning) using the dresser member.

If the dressing of the polishing pad 12 is incorporated before or after the polishing of the wafer, the tact time becomes long, the processing cannot be performed efficiently, and it is difficult to improve the productivity. Also, a wafer polishing step,
In the dressing step of the polishing surface 52 of the surface plate, the conditions of the pressing force and the speed (the number of rotations) are different, but in the conventional method, the wafer holding plate 64 is used in both the polishing step and the dressing step. For this reason, the number of rotations of the wafer holding plate 64 and the pressure applied to the wafer holding plate 52 (the pressure supplied to the pressure chamber) are switched with the switching between the wafer polishing process and the dressing process of the polishing surface 52 of the surface plate. Had to be changed each time. Therefore, if the polishing step and the dressing step are incorporated as a series of steps, the operation becomes complicated, the workability is poor, and as a result, it is difficult to improve the productivity.

Accordingly, an object of the present invention is to minimize the occurrence of deformation, wear, and the like on the polishing surface of a polishing cloth or the like during wafer processing, and to reduce the flatness of the polishing surface of the platen formed by the polishing cloth or the like. It is an object of the present invention to provide a wafer polishing apparatus which can maintain the polishing property appropriately, improve the polishing accuracy of the wafer, and have excellent operation efficiency.

[0009]

To achieve the above object, the present invention has the following arrangement. That is, the present invention
A holding device for holding the wafer, and a surface plate having a polished surface for polishing the surface to be polished of the wafer held by the holding device, the relative movement of the holding device and the surface plate In a wafer polishing apparatus for polishing a surface to be polished of a wafer, the holding device includes an inner head member provided with a concave portion opened toward the polishing surface of the surface plate, and a concave portion incorporating the inner head member. An outer head member opened toward the polishing surface of the surface plate is provided so as to be rotatable at an individual number of revolutions, and the inner head member is disposed in a concave portion thereof, and a wafer is provided. A wafer holding plate on which a holding surface to be held is formed, an outer peripheral portion and an inner peripheral portion are fixed to the outer peripheral portion of the concave portion of the inner head member and the wafer retaining plate, and the wafer retaining plate is vertically moved with respect to the concave portion. Allow to move to etc. And an elastic suspending member that defines the inside of the concave portion of the inner head member together with the wafer holding plate to form a wafer pressurizing pressure chamber, and the outer head member has an outer peripheral side portion thereof. And an intermediate peripheral side portion located between the outer peripheral portion of the inner head member and surrounding the inner head member, and formed into a ring shape so that the polishing surface of the surface plate can be pressed and dressed to be flattened. A dresser member that is formed and surrounds the wafer holding plate, an outer peripheral portion and an inner peripheral portion are fixed to the outer peripheral side portion and the intermediate peripheral side portion, and the dresser member is attached to the outer peripheral side portion and the intermediate peripheral side portion. vertical direction, such as with suspended Jisuru and allowed to move, is constituted by a strip ring-like elastic member to form a dresser pressurizing the pressure chamber with the outer circumference side and the intermediate peripheral side portion, and the intermediate with respect to The peripheral side is The side head member
Formed as a separate part, via the band ring-shaped elastic member
Is provided so as to operate integrally with the outer head member.
And rotatable with respect to the inner head member.
Supports the members constituting the inner head member via bearings.
Are lifting, by supplying a predetermined pressure of fluid to the wafer pressurizing the pressure chamber to press the wafer on the polishing surface of the platen through the wafer holding plate, the fluid of a predetermined pressure to the dresser pressurizing the pressure chamber Pressurizing means for supplying and pressing the dresser member against the polishing surface of the surface plate is provided.

Further, the wafer pressurizing means for pressing the c Eha pressurizing the pressure pressure chamber for supplying a predetermined pressure of the fluid through the U Eha retaining disc Siu Eha the polishing surface of the platen, de suppressor pressurizing the pressure chamber in that the dresser member pressing means for pressing are provided separately in a fluid polishing surface of the platen to de suppressor member by supplying a predetermined pressure, the speed and the dresser member for polishing the wafer The speed and the speed can be individually adapted. For this reason, processing under optimal conditions becomes possible, and polishing accuracy can be improved.

Furthermore, an inner head rotating device for rotating an axis orthogonal to the inner side head member on the polished surface of the window Eha held in the U Eha retaining disc to the center, c E outer side head member <br / > by including an outer head rotating device that rotates around the axis perpendicular to the surface to be polished of the c Eha held in Doha holding plate, the rotational speed of the rotational speed and the dresser member for polishing the wafer And can be individually adapted. For this reason, processing under optimal conditions becomes possible, and polishing accuracy can be improved.

[0012]

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a wafer polishing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. (First Embodiment) FIG. 1 is a sectional view for explaining a holding device which is a main part of an embodiment (first embodiment) of a wafer polishing apparatus according to the present invention, and FIG. 2 is a first embodiment. FIG. 4 is a cross-sectional view showing a region into which high-pressure air flows. FIG. 3 is an explanatory view for explaining a situation in which the polishing surface of the polishing cloth is dressed by the wafer polishing apparatus shown in FIGS. FIG. 4 is an explanatory view for explaining the shape of the surface of the dresser member which comes into contact with the polishing pad, and FIG. 5 is a sectional view showing a drive mechanism and the like of the first embodiment. The first embodiment is a wafer polishing apparatus for polishing a surface to be polished of a silicon wafer (hereinafter, simply referred to as a "wafer"), and a holding apparatus 10 for holding a wafer, and a wafer held by the holding apparatus 10. Polishing surface 52 for polishing the surface 12a to be polished 12
The holding device 10 and the surface plate 5 are provided.
And the surface 12 to be polished of the wafer 12
a is polished.

The holding device 10 includes an inner head member 20 provided with a concave portion 21 opened toward a polishing surface 52 of a surface plate.
And an outer head member 30 provided with a concave portion 31 containing the inner head member 20 opened toward the polishing surface 52 of the surface plate.

The inner head member 20 has a wafer holding plate 22 disposed in a recess 21 of the inner head member 20 and having a holding surface 22a on which the wafer 12 is held.
The inner head member 20 and the wafer holding plate 22 are fixedly arranged on the both, and the wafer holding plate 22 is suspended while being allowed to move in the vertical direction with respect to the inner head member 20. An elastic suspension member 24 which defines the inside of the head member 20 together with the wafer holding plate 22 to form a wafer pressurizing pressure chamber 25 is provided.

Next, the inner head member 20 and the structure provided in the inner head member 20 will be described in more detail. The inner head member 20 forms a base of a part of the holding device 10 that holds the wafer 12 as a work. The inner head member 20 is provided with a recess 21 that opens downward.

The wafer holding plate 22 has a wafer 1 on its lower surface.
2 is provided inside the outer peripheral portion 20a of the inner head member 20 so as to be surrounded by the outer peripheral portion 20a. Further, the holding surface 22a is positioned so as to protrude below the lower surface of the outer peripheral portion 20a. In the first embodiment, the holding surface 22a of the wafer holding board 22
It is formed on an attaching surface on which the wafer 12 is attached via water. A backing material (not shown) is adhered to the holding surface 22a. This backing material has a surface with a high adsorptivity, and has a function (water application function) of securely attaching the wafer 12 by the surface tension and viscosity of a liquid such as water.

In the case of the holding surface 22a having a water application function, a ring-shaped so-called template surrounding the wafer 12 is mounted on the holding surface 22a in order to prevent the wafer 12 from skidding. Generally, the inner diameter of this template is set to be about 1 mm or less (for example, 0.3 mm) larger than the outer diameter of the wafer 12. The diameter of the wafer 12 according to the present embodiment is, for example,
A size of about 300 mm is assumed. As described above, the dimensional difference between the inner diameter of the template and the outer diameter of the wafer 12 fitted to the inner diameter is extremely smaller than the size of the wafer 12. The thickness of the template is
It is set to be thinner. Incidentally, in order to obtain the function of preventing the side slip of the wafer 12, it is not limited to mounting the above-described template on the holding surface 22a. For example, the diameter of the holding surface 22a may be set to be the same as the diameter of the wafer 12, and a dresser member 36 described later may be used so as to perform the same function as the above-described template. This makes it possible to further prevent the outer peripheral portion of the wafer 12 from sagging. This is the dresser member 3
6 presses the polishing cloth 51 corresponding to the portion surrounding the outer periphery of the wafer 12, so that the force of crushing the polishing cloth 51 by the outer periphery of the wafer 12 is small and good.

In this embodiment, the elastic suspension member 24 is formed in a plate shape by an elastic material. More specifically, it is formed in a donut shape by a hard rubber plate material (nitrile rubber with cloth in this embodiment). This elastic suspension member 2
4, in the present embodiment, the outer peripheral portion 24 b of the elastic suspension member is fixed to the outer peripheral portion 20 a which is the peripheral wall portion on the inner head member 20 side, and the inner peripheral portion 24 a of the elastic suspension member is
Is fixed to the upper surface of the outer edge 22b. More specifically, the outer peripheral portion 24b of the elastic suspension member is
It is sandwiched between upper and lower members constituting the outer peripheral portion 20a of the “0”, and is fixed by being bolted (not shown). Further, the inner peripheral portion 24a of the elastic suspension member is sandwiched between the wafer holding plate 22 and the pressing member 23, and is fixed by being tightened by bolts (not shown). Thereby, the elastic suspension member 24 moves the wafer holding plate 22 in the vertical direction or the like (including the horizontal direction) with respect to the inner head member 20.
Hanging to allow to move to.

The wafer pressurizing pressure chamber 25 is provided so that the inside of the inner head member 20 is defined by a wafer holding plate 22 and an elastic suspension member 24. Pressurized means 28 supplies compressed air, which is a fluid of a predetermined pressure, into the wafer pressurizing chamber 25. By pressing the wafer pressurizing chamber 25 by the pressurizing means 28, the wafer 12 can be pressed against the polishing surface 52 of the surface plate via the wafer holding plate 22, and the polished surface 12a of the wafer 12 can be suitably polished. The pressurizing means 28 is provided with a pressure adjusting device (not shown) for adjusting the pressure of the compressed air supplied to the wafer pressurizing pressure chamber 25.

The outer head member 30 has an outer peripheral side portion 30a and an intermediate portion located between the outer peripheral side portion 30a and the outer peripheral portion 20a of the inner head member 20 so as to double surround the inner head member 20. A peripheral side portion 33 is provided. A dresser member 36 for dressing the polishing surface 52 of the surface plate is suspended between the outer peripheral side portion 30a and the intermediate peripheral side portion 33 to define the inside of the outer head member 30 and to form a pressure chamber for dresser pressurization. A band ring-shaped elastic member 34 forming 35 is provided. The dresser member 36 suspended from the band ring-shaped elastic member 34 has an L-shaped cross-sectional shape, is formed in a ring shape so as to surround the wafer holding plate 22, and has an outer head. The member 30 is allowed to move in a vertical direction or the like.

Next, the outer head member 30 and the structure provided in the outer head member 30 will be described in more detail. The outer head member 30 forms a base outside the portion for holding the wafer 12 as a work in the holding device 10. The outer head member 30 has an upper surface portion 30b, which is a disk-shaped base portion, and an outer peripheral side portion 30a, which is a side peripheral wall portion, integrally formed. Is provided in the concave portion 31 that opens downward.

Further, the intermediate peripheral side portion 33 of this embodiment is formed as a separate component from the outer head member 30 and is provided so as to operate integrally with the outer head member 30 via a band ring-shaped elastic member 34. At the same time, the inner head member 20 is rotatably mounted on the inner head member 20 with a bearing 4.
0 is supported. Also, the intermediate peripheral side portion 33 is
The bowl is turned upside down and provided in a shape with a central part opened, a seal ring 41 is arranged on the inner peripheral edge of the opening,
The seal ring 41 seals (airtightly) the space between the inner head member 20 and the intermediate peripheral side portion 33 so as to define the pressure chamber 35 for dresser pressurization. As described above, the outer head member 30 including the inner head member 20 and the intermediate peripheral side portion 33 is provided in a state in which the pressure chamber 35 for pressurizing the dresser is suitably airtight by interposing the bearing 40 and the seal ring 41.
And can be suitably positioned separately rotatably.

In this embodiment, the band ring-shaped elastic member 34 is formed in a plate shape by an elastic material. More specifically, it is formed in a donut shape by a hard rubber plate material (nitrile rubber with cloth in this embodiment). In this embodiment, the band ring-shaped elastic member 34 has an outer peripheral portion 34b of the band ring-shaped elastic member 34 fixed to an outer peripheral side portion 30a of the outer head member 30, and an inner peripheral portion 34a of the band ring-shaped elastic member.
Is an intermediate peripheral side portion 33 which rotates integrally with the outer head member 30.
It is fixed to. More specifically, the outer peripheral portion 34b of the band ring-shaped elastic member 34 is sandwiched between upper and lower members constituting the outer peripheral side portion 30a, and is fixed by being bolted (not shown). Further, the inner peripheral portion 34a of the band ring-shaped elastic member is sandwiched between upper and lower members constituting the intermediate peripheral side portion 33, and is fixed by being bolted (not shown). And the band ring-shaped elastic member 3
A dresser member 36 having a dresser surface facing the polishing surface 52 of the surface plate is fixed to the lower surface of the plate 4. As a result, the band ring-shaped elastic member 34 is
Is suspended with respect to the inner head member 20 so as to be able to move in the vertical direction and the like (including the horizontal direction and the like).

The pressure chamber 35 for pressurizing the dresser is provided such that the inside of the outer head member 30 is defined by a band-ring elastic member 34. This dresser pressurizing pressure chamber 35
Compressed air, which is a fluid at a predetermined pressure, is introduced into
Supplied by By pressing the pressure chamber 35 for dresser pressurization by the pressurizing means 28, the member 36 for dresser
Can be pressed against the polishing surface 52 of the surface plate, and the polishing surface 52 of the surface plate can be suitably dressed, so that the polishing surface 52 can be flattened. The pressing means 28 for pressing the dresser of the first embodiment is the same as the pressing means 2 for pressing the wafer.
8 is shared. That is, as shown by hatching with parallel oblique lines in FIG. 2, compressed air (high-pressure air)
Is supplied from the axial center portion, flows into the wafer pressurizing pressure chamber 25, and at the same time, the upper surface portion 20b of the inner head member.
Pressure chamber 3 for pressurizing the dresser through a through hole 26 provided in
5 is also supplied. As a result, the wafer 12 and the dresser member 36 can be simultaneously pressed against the polishing surface 52 of the platen.

FIG. 3 shows a state in which the polishing surface 52 of the surface plate can be dressed favorably by the dresser member 36.
In FIG. 3, the compressed air flowing into the wafer pressurizing pressure chamber 25 causes the wafer surface 12 a to move the polishing pad 52.
At a predetermined pressing force. At the same time, the compressed air that has flowed into the wafer pressure chamber 25 also flows into the dresser pressure chamber 35, and presses the surface formed parallel to the polishing surface 51 of the dresser member 36. In this way, the surface in the vicinity of the polishing surface 51 pressed by the wafer surface 12a is pressed by the dresser member 36. For this reason, as shown in FIG. 10, the corners of the wafer 12 come into contact with the side wall surfaces of the recesses formed by pressing the wafer surface 12a and are polished. The occurrence of wear and the like can be prevented as much as possible, and the number of times of dressing in a step separate from the polishing step can be reduced as much as possible. Such a dresser member 36
For example, diamond abrasive grains fixed on the surface of a metal disk or mesh disk, and the surface coated with a diamond CVD film can be used. In addition, as the dresser member 36, a welding grindstone or ceramic is used,
When the surface is appropriately rough, the polishing surface 52 of the surface plate can be dressed efficiently and the polishing surface 52 can be flattened. The dresser member 36 of the present embodiment is formed in a ring shape as a whole, and has a thickened portion 36a which is thicker upward on the outer peripheral portion so as to be suitably fixed to the band ring-shaped elastic member 34. Have been. Band ring-shaped elastic member 34
Is sandwiched between the thick portion 36a and the pressing member 36b and tightened by a bolt (not shown), so that the dresser member 36 is fixed to the band ring-shaped elastic member 34. Further, in the dresser member 36 of the present embodiment, a flat dresser surface 36c extends from the outer peripheral portion provided with the thick portion 36a toward the inner peripheral portion, and the inner peripheral edge thereof extends to near the outer periphery of the wafer holding plate 22. Has reached. That is, the inner peripheral portion of the dresser member 36 includes the intermediate peripheral portion 33 and the outer peripheral portion 2.
0a from the lower side to the vicinity of the outer periphery of the wafer holding plate 22 is formed in a protruding state. This allows
Dresser surface 3 of dresser member 36 with good space efficiency
6c is formed.

As for the shape of the dresser member 36, the dresser member 36 is located around the outer circumference (entire circumference) of the wafer 12 and comes into contact with the polishing surface 52 (polishing cloth 51). (Slurry) is less likely to be supplied to the polishing cloth 51 for polishing the wafer 12. For this purpose, as shown in FIG. 4, a groove 36d through which the slurry passes may be formed on the surface of the dresser member 36 that contacts the polishing pad 51. In addition, if the planar shape of the groove 36d is a curve along the rotation direction (arrow R) of the dresser member 36, the slurry can flow into the interior appropriately (arrow S).
Indicates the flow direction of the slurry). In addition, the cross-sectional shape of the groove 36d includes a V shape, a square shape, and the like, but the shape is not particularly limited. Thus, groove 3
The provision of 6d is suitably applied to the case where the diameter of the platen 50 is considerably larger than the diameter of the wafer 12, for example, when the diameter of the platen 50 is equal to or slightly larger than the diameter of the wafer 12 ( In the case where the surface plate 50 is small), the polishing cloth 5 with which the polished surface 12a of the wafer 12 contacts
1 (polishing surface 52), the platen 50
Alternatively, a through-hole (slurry supply hole) may be provided in the polishing pad 51, and the slurry may be ejected (supplied) from below. This is because it is difficult to effectively supply slurry from the outside to the entire surface to be polished 12a of the wafer 12 when the platen 50 is small or the like.

According to the dresser member 36, the polishing of the polished surface 52 of the platen can be performed simultaneously with the polishing of the wafer 12, and the deformation and wear of the polished surface 52 of the platen can be suitably prevented. can do. Therefore, the production process (tact time) can be shortened, and the production efficiency can be improved. In addition, since the flatness of the polished surface 52 of the platen can be constantly maintained, a wafer with high polishing accuracy can be produced. Further, even in the case of performing polishing in which dressing of the polishing cloth needs to be performed in a step separate from the polishing step, the frequency of inserting a dressing step of performing only dressing during polishing can be reduced as much as possible. , The production efficiency can be improved.

Next, the rotation drive mechanism and the elevating mechanism of the inner head member 20 and the outer head member 30 will be described below. Reference numeral 42 denotes an inner bearing, which is disposed between the outer periphery of the inner peripheral shaft member 27 provided integrally with the inner head member 20 and the inner periphery of the outer peripheral shaft member 37 provided integrally with the outer head member 30. Are provided so as to be able to rotate around the axis at different rotational speeds. Reference numeral 43 denotes an inner seal ring, which is provided outside the inner peripheral shaft member 27 provided integrally with the inner head member 20 and the outer head member 3.
It is provided between the inside of the outer peripheral shaft member 37 provided integrally with the first member 0 and hermetically seals the space therebetween.

Reference numeral 44 denotes an inner head rotating device, which is configured to rotate the inner head member 20 around an axis perpendicular to the polished surface 12a of the wafer held by the wafer holding plate 22. . As shown in FIG. 5, reference numeral 45 denotes a drive motor for the inside head, and a pinion gear 45a is fixed to the output shaft. Reference numeral 46 denotes a driven gear, which is fixed to the upper end of the inner peripheral shaft member 27 and meshes with the pinion gear 45a. An upper bearing portion 47 is provided so that the inner peripheral shaft member 27 can rotate smoothly with respect to the outer peripheral shaft member 37. According to this, the inside head member 20 fixed to and integrated with the lower end of the inner peripheral shaft member 27 via the elongated inner peripheral shaft member 27 can be suitably rotated by the inner head drive motor 45. Thus, the wafer 12 held by the inner head member 20 (wafer holding plate 22) can be suitably rotated (rotated) about an axis perpendicular to the surface to be polished.

Numeral 54 denotes an outer head rotating device,
The outer head member 30 is configured to rotate around an axis perpendicular to the polished surface 12a of the wafer held on the wafer holding board 22. As shown in FIG.
Reference numeral 5 denotes a drive motor for the outer head, and a pinion gear 55a is fixed to the output shaft. 56 is a driven gear,
It is fixed to the outer peripheral shaft member 37 side so as to operate integrally with the outer peripheral shaft member 37 side, and meshes with the pinion gear 55a. Reference numeral 58 denotes a bearing portion, which is provided above and below, and which is provided on the outer
Are provided so that they can rotate smoothly. According to this, the outer head driving motor 55 can suitably rotate the integrated outer head member 30 fixed to the lower end of the outer peripheral shaft member 37 via the elongated outer peripheral shaft member 37. Thereby, the dresser member 36 held on the outer head member 30 via the band ring-shaped elastic member 34 is
The wafer can be suitably rotated (rotated) about an axis perpendicular to the polished surface 12a of the wafer.

As described above, by separately providing a rotation device (rotation drive mechanism wafer) for the inner head member 20 and the outer head member 30, the rotation speed for polishing the wafer and the rotation speed for the dresser member are individually set. Can be adapted. For this reason, processing under optimal conditions becomes possible, and polishing accuracy can be improved.

As shown in FIG. 5, reference numeral 74 denotes a cylinder device, which is an inner head member 20 and an inner head member 2.
The head mechanism including the inner shaft member 27 and the outer shaft member 37 is driven to move up and down as a whole. The cylinder device 74 includes a cylinder 74 a on the support base member 14.
The rear end of the rod 74b is fixed, and the tip of the rod 74b is fixed to the elevating body 76 via the connecting member 75. The above-described inner head drive motor 45 is fixed on the elevating body 76. The elevating body 76 has a bearing 7 on which the outer peripheral shaft member 37 does not move up and down with respect to the elevating body 76 and receives a load in the thrust direction.
7, so as to be rotatable about the axis. In addition, the inner peripheral shaft member 27 does not move up and down with respect to the outer peripheral shaft member 37 via the upper bearing portion 47 and the inner bearing portion 42 by the stopper portion 79 fixed to the upper portion. It is held so that it can rotate around. Therefore, as a result, the inner peripheral shaft member 27 also
The elevating body 76 does not fall and is held rotatably about the axis.

Reference numeral 14a denotes a support cylinder, which is formed to extend upward from the support base member 14. An outer peripheral shaft member 37 is inserted vertically inside the support cylindrical portion 14a so as to be able to move up and down along the axis, and the key 16 is rotated by the key 16 around the outer peripheral shaft member 37 and the axis. The connected inner cylinder connecting member 78 is provided. The driven gear 56 is externally fitted and fixed to the inner cylinder connecting member 78 as described above, and the driven gear 56 is engaged with the pinion gear 55a of the outer head drive motor 55. The outer head drive motor 55 is fixed on the support base member 14. Thus, when the outer head drive motor 55 is driven to rotate, the outer head member 30 can be rotated via the outer peripheral shaft member 37. Further, by operating the cylinder device 74, the outer peripheral shaft member 37 slides inside the inner cylinder connecting member 78, and the head mechanism can be entirely moved up and down as described above. With the above-described drive mechanism, the contact / separation movement for moving the wafer 12 toward and away from the polishing surface 52 of the surface plate (elevation) so that the surface of the wafer (the surface to be polished 12a) is brought into contact with the polishing surface 52 of the surface plate. Means for rotating the wafer 12 and the dresser member 3
Rotation means for rotating the rotating member 6 is constituted.

Reference numeral 29 denotes a connection port, and the inner peripheral shaft member 2
7 is provided along the axis of the inner peripheral shaft member 27 and communicates with the pressure chamber 25 for pressurizing the wafer. In the case of air pressure, the pressurizing means 28 is specifically a compressor. In addition, it goes without saying that the connection port 27 may have a distributor function of preventing the pipe from being twisted even by rotation (rotation). Although not shown, the basic configuration of the wafer polishing apparatus includes a means for supplying a liquid abrasive containing a slurry or the like.

(Second Embodiment) Next, a second embodiment will be described.
A description will be given based on FIG. 6 and FIG. About the same composition as a 1st example, the same numerals as those given in Drawings 1-4 are attached, and explanation is omitted. FIG. 6 is a sectional view for explaining a holding device which is a main part of a second embodiment of the wafer polishing apparatus according to the present invention. FIG. 7 is a cross-sectional view showing a region into which high-pressure air according to the second embodiment flows. A feature of the second embodiment is that a fluid at a predetermined pressure is supplied to the wafer pressurizing pressure chamber 25 and the wafer 12 is supplied through the wafer holding plate 22.
A fluid of a predetermined pressure is supplied to the wafer pressurizing means 38 for pressing the (polished surface 12a) against the polishing surface 52 of the surface plate, and a fluid of a predetermined pressure to the pressure chamber 35 for dresser pressurization, and the dresser member 36 is moved to the polishing surface 52 of the surface plate. This is in that the dresser member pressing means 39 for pressing is provided separately. For this reason, a connection port 39a for supplying a fluid of a predetermined pressure (high-pressure air in this embodiment) from the dresser member pressurizing means 39 to the dresser pressurizing pressure chamber 35 is connected to the outer head member 30 (upper surface portion 30b). The through hole 26 is not formed as in the first embodiment.

That is, as shown in FIG. 7, the portion indicated by hatching with parallel diagonal lines is the wafer pressurizing pressure chamber 25 to which high-pressure air is supplied from the wafer pressurizing means 38. The hatched portion in the form of a mesh is the pressure chamber 35 for pressurizing the dresser to which high-pressure air is supplied from the pressurizing means 39 for the dresser. According to this, a fluid (high-pressure air) having a pressure separately adjusted can be supplied to the wafer pressurizing pressure chamber 25 and the dresser pressurizing pressure chamber 35, and the pressure for pressing the wafer 12 and the pressure for pressing the dresser member are provided. Can be controlled separately. Therefore, the dresser member can be pressed against the polishing cloth with a pressing force corresponding to the pressing force of the wafer against the polishing surface of the polishing cloth, and the flatness of the polishing surface of the polishing cloth can be further maintained. For this reason, processing under optimal conditions becomes possible, and polishing accuracy can be improved. In addition, the wafer pressing means 38
A pressure adjusting device (not shown) for adjusting the pressure of the fluid supplied to the wafer pressurizing pressure chamber 25 is provided, and the pressure of the fluid supplied to the dresser pressurizing pressure chamber 35 is supplied to the dresser member pressurizing means 39. If a decompression adjusting device (not shown) for adjusting is provided, each pressure chamber 38, 39 is adjusted by adjusting them.
Can be suitably controlled, and a common pressure source may be used.

Further, a decompression means is connected to the wafer pressure chamber 25 separately from the wafer pressurization means 38, and the depressurization means functions to suck up the wafer holding plate 22.
By operating the dresser member pressing means 39, only the dresser member 36 is brought into contact with and pressed against the polishing surface 52 of the surface plate via the band ring-shaped elastic member 34, and the polishing surface 52 of the surface plate is dressed only. It can be performed. The dressing member pressurizing means 39 is provided in the dresser pressurizing pressure chamber 35.
Separately, a pressure reducing means is connected, the function of the pressure reducing means causes the dressing member 36 to be sucked up through the band-ring-shaped elastic member 34, and the function of the wafer pressing means 38 causes the polished surface of the wafer 12 Only 12a is brought into contact with and pressed against the polishing surface 52 of the platen via the wafer holding plate 22,
Only the polishing of the polished surface 12a of the wafer 12 can be performed.

[0039]

Further, in the above embodiment, the case where the holding surface 22a of the wafer holding board 22 is formed on the attaching surface to which the wafer 12 is attached via water has been described.
The present invention is not limited to this. For example, the holding surface 22a of the wafer holding board 22 may be formed on a suction surface that suctions the wafer 12 by suction under reduced pressure, and the wafer 12 may be sucked by a vacuum device. Further, it is possible to securely attach the wafer 12 to the holding surface 22a by bonding. Alternatively, the centering action may be obtained by a mechanism configured by one tapered fitting portion 70 and the other tapered fitting portion 72 described in the section of the related art.

In the above-described embodiment, the wafer 12 is polished to the polishing surface 5 through the wafer holding plate 22 by air pressure.
Although the case of pressing (pressing) to 2 has been described, other fluid pressure, for example, water pressure or oil pressure can be used. Further, according to the wafer polishing apparatus described above, a wafer-like work (for example, a surface of a hard brittle thin plate material such as a glass thin plate material or quartz crystal) can be suitably polished in addition to a silicon wafer. As described above, various preferred embodiments of the present invention have been described. However, the present invention is not limited to these embodiments, and it goes without saying that many more modifications can be made without departing from the spirit of the invention. That is.

[0042]

According to the present invention, the surface to be polished of the wafer is pressed against the polishing surface of the surface plate via the wafer holding plate by the fluid pressure supplied to the pressure chamber for wafer pressing provided in the inner head member. The dresser member can be pressed against the polishing surface of the platen by the fluid pressure supplied to the dresser pressurizing pressure chamber provided in the outer head member. Furthermore, the wafer
The number of rotations of the holding plate and the dresser member can be individually handled
What it coupled with, during lapping of the c Eha, the member for dresser is pressed against the polishing surface of the platen, it is possible to maintain the flatness of the polished surface of the plate formed by the polishing cloth and the like. But
Therefore , according to the present invention, it is possible to improve the polishing accuracy of the wafer and to improve the operation efficiency.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a holding device, which is a main part, of a first embodiment of a wafer polishing apparatus according to the present invention.

FIG. 2 is a cross-sectional view illustrating a region into which high-pressure air flows according to the first embodiment.

FIG. 3 is an explanatory view illustrating a situation where a polishing surface of a polishing cloth is dressed by the wafer polishing apparatus shown in FIGS. 1 and 2;

FIG. 4 is an explanatory diagram illustrating a shape of a surface of a dresser member that contacts a polishing cloth.

FIG. 5 is a sectional view showing a drive mechanism and the like of the first embodiment.

FIG. 6 is a sectional view for explaining a holding device which is a main part of a second embodiment of the wafer polishing apparatus according to the present invention.

FIG. 7 is a cross-sectional view illustrating a region into which high-pressure air flows in a second embodiment.

FIG. 8 is a sectional view showing a conventional technique.

FIG. 9 shows a conventional wafer polishing apparatus shown in FIG .
FIG. 4 is an explanatory view illustrating a state of a polishing surface of a polishing cloth.

Continuation of the front page (72) Inventor Yoshio Nakamura 1650 Kiyono, Matsushiro-machi, Nagano City, Nagano Prefecture Inside Fujikoshi Machinery Co., Ltd. (56) References JP-A-4-343658 (JP, A) JP-A-11-77519 (JP, A) JP-A-9-254020 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24B 37/00 B24B 53/02 H01L 21/304 622

Claims (3)

(57) [Claims] 1. A holding device for holding a wafer, and a surface plate having a polished surface for polishing a surface to be polished of the wafer held by the holding device, wherein the holding device and the surface plate are relatively A polishing apparatus for polishing a surface to be polished of a wafer by moving the wafer, wherein the holding device has an inner head member provided with a concave portion opened toward the polishing surface of the surface plate; An outer head member provided with a concave portion containing a member opened toward the polishing surface of the surface plate is provided rotatably at an individual rotation speed, and the inner head member is provided in the concave portion. A wafer holding plate on which a holding surface for holding a wafer is formed, an outer peripheral portion and an inner peripheral portion are fixed to an outer peripheral portion of the concave portion of the inner head member and the wafer retaining plate, and the wafer retaining plate is recessed. Up and down direction And an elastic suspension member that defines the inside of the concave portion of the inner head member together with the wafer holding plate to form a wafer pressurizing pressure chamber, and that the outer head member is An intermediate peripheral side portion located between the outer peripheral side portion and the outer peripheral portion of the inner head member and provided so as to surround the inner head member, and the polishing surface of the surface plate can be pressed and dressed to be flattened. A dresser member that is formed in a ring shape and surrounds the wafer holding plate, and an outer peripheral portion and an inner peripheral portion are fixed to the outer peripheral side portion and the intermediate peripheral side portion, and the dresser member is attached to the outer peripheral side portion. And a belt-ring-shaped elastic member that suspends while allowing it to move in the vertical direction and the like with respect to the intermediate peripheral side portion and forms a pressure chamber for dresser pressurization together with the outer peripheral side portion and the intermediate peripheral side portion. It is, and the intermediate Sides, a separate part from said outer head member
Formed through the belt ring-shaped elastic member
Provided to operate integrally with the outer head member
With the inner head member rotatably with respect to the inner head member.
Supported by a member constituting the pad member via a bearing.
And which supplies a predetermined pressure of fluid to the wafer pressurizing the pressure chamber to press the wafer on the polishing surface of the platen through the wafer holding plate, supplying a predetermined pressure of fluid in the dresser pressurizing the pressure chamber A polishing means for pressing the dresser member against a polishing surface of a surface plate. 2. A wafer pressurizing means for supplying a fluid of a predetermined pressure to a wafer pressurizing pressure chamber to press a wafer against a polishing surface of a surface plate via a wafer holding plate, and a fluid of a predetermined pressure to a dresser pressurizing pressure chamber. 2. A wafer polishing apparatus according to claim 1, further comprising a dresser member pressurizing means for supplying the pressure and pressing the dresser member against the polishing surface of the platen. 3. An inner head rotating device for rotating an inner head member about an axis perpendicular to a surface to be polished of a wafer held on a wafer holding plate, and an outer head member for rotating a wafer held on the wafer holding plate. 3. The wafer polishing apparatus according to claim 1, further comprising an outer head rotating device that rotates about an axis perpendicular to the surface to be polished.