JP2018034299A - Suction holding device and wafer polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suction holding device capable of surely fixing an intake plate with respect to a base, and a wafer polishing device.SOLUTION: The suction holding device is provided with: an intake plate 3 that has a front surface 31 and a rear surface 32 opposed to each other and that is made of a ventilative material; a fixing member 2 that has a through-hole 23 in which the intake plate 3 is arranged; and a base 1 which is positioned on the rear surface 32 side of the intake plate 3 and to which the fixing member 2 is fitted. The intake plate 3 has a bulged part 34 in which an outer edge 32a of the rear surface 32 bulges more outside than an outer edge 31a of the front surface 31. The fixing member 2 has an eaves part 24 in which an end edge 23a of the through-hole 23 opposed to the base 1 is positioned more inside than the outer edge 32a of the rear surface 32 in the bulged part 34 in the thickness view of the intake plate 3. The base 1 has a bottom surface 12 directly opposed to the rear surface 32 of the intake plate 3. A suction hole 13 is formed in the bottom surface 12. The intake plate 3 has a recessed part 36 that includes the suction hole 13 in the thickness view and that is recessed from the rear surface 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a suction holding apparatus and a wafer polishing apparatus.

  In a wafer polishing apparatus for polishing a semiconductor wafer, the semiconductor wafer is polished by a polishing means having a polishing pad, for example. At this time, in addition to adjusting the semiconductor wafer to a predetermined thickness, it is required to finish the surface of the semiconductor wafer very smoothly. For this reason, it is important to securely hold the semiconductor wafer in a flat state. An example of a suction holding device for holding such a semiconductor wafer is disclosed in Patent Document 1.

  The suction holding device disclosed in Patent Document 1 includes a base and an intake plate. A circular recess is formed in the base. A plurality of suction holes are provided on the bottom surface of the recess. These suction holes are connected to a suction source such as a pump so that suction is possible.

  The intake plate is disposed so as to be fitted into the recess of the base. The intake plate is further configured by arranging a plurality of annular elements concentrically. These annular elements include, for example, a highly air permeable annular element made of a material having air permeability such as porous ceramics, and a low air permeable annular element that hardly exhibits air permeability. The breathable annular elements are arranged alternately. Further, the low air permeability annular element has a remarkably small radial dimension compared to the high air permeability annular element, and functions as a so-called blocking wall that blocks ventilation.

  When polishing in the wafer polishing apparatus, the semiconductor wafer to be polished is placed on the suction plate by the suction holding apparatus. Then, suction from the suction hole is performed. By this suction, a suction force acts on the semiconductor wafer through the highly air-permeable annular element of the suction plate. With this suction force, the semiconductor wafer is held by the suction holding device and is ready for polishing. In the suction holding apparatus, the plurality of suction holes are divided into several groups and connected to the suction source. By controlling the suction of each group using, for example, a valve, the suction force is exerted only on the above highly air-permeable annular element corresponding to the size from a relatively small diameter semiconductor wafer to a relatively large diameter semiconductor wafer. It is possible to make it.

  For example, an adhesive is used to fix the intake plate having a portion made of porous ceramics or the like to the base. With this adhesive, the intake plate is bonded to the bottom surface of the concave portion of the base. However, compression force and shearing force from the polishing means are repeatedly applied to the intake plate through the semiconductor wafer. For this reason, after many times of polishing, the adhesive force of the adhesive decreases, and any of the plurality of annular elements of the intake plate may be peeled off from the base. When such peeling occurs, a fine step is generated on the surface of the air intake plate, which causes a problem that the semiconductor wafer is not properly held.

JP 2000-158268 A

  The present invention has been conceived under the circumstances described above, and it is an object of the present invention to provide a suction holding apparatus and a wafer polishing apparatus that can more reliably fix an intake plate to a base.

  The suction holding device provided by the first aspect of the present invention has a suction plate made of a material having air permeability and having a front surface and a back surface facing opposite to each other, and a through hole. A fixing member on which the suction plate is disposed, and a base on which the fixing member is attached and located on the back surface side of the suction plate. The fixing member has a protruding portion that protrudes outward from the outer edge, and the fixing member has an end edge of the through hole that is located on the opposite side of the base, and the back surface of the protruding portion in the thickness direction of the intake plate It has the eaves part located inward rather than the outer edge of.

  In a preferred embodiment of the present invention, at least a part of the intake plate is made of porous ceramics.

  In preferable embodiment of this invention, the said fixing member consists of ceramics which do not have air permeability.

  In a preferred embodiment of the present invention, the fixing member has a surface that is flush with the surface of the intake plate.

  In a preferred embodiment of the present invention, the projecting portion of the intake plate has an inclined surface that connects the outer edge of the front surface and the outer edge of the rear surface.

  In a preferred embodiment of the present invention, the projecting portion of the intake plate has a step located between the outer edge of the front surface and the outer edge of the rear surface.

  In a preferred embodiment of the present invention, the protruding portion of the intake plate is provided on the entire circumference of the intake plate, and the eaves portion of the fixing member is provided on the entire periphery of the fixing member.

  In a preferred embodiment of the present invention, the two overhang portions of the intake plate are provided apart from each other, and the two eaves portions of the fixing member are provided apart from each other.

  In a preferred embodiment of the present invention, the intake plate has an upstanding side surface that is sandwiched between the two projecting portions and that stands along the thickness direction of the intake plate. It has an upright side surface sandwiched between two eaves portions and upstanding along the thickness direction of the intake plate.

  In a preferred embodiment of the present invention, the air intake plate is composed of a plurality of annular elements whose centers coincide with each other, and each of the annular elements has an outer edge of the back surface protruding outward from an outer edge of the surface. It has an overhang | projection part and the eaves part which the inner edge of the said surface is located inward rather than the inner edge of the said back surface.

  In a preferred embodiment of the present invention, the plurality of annular elements include a highly air permeable annular element having a relatively high air permeability and a low air permeable annular element having a relatively low air permeability, and has a high air permeability. The annular elements and the low air permeability annular elements are arranged alternately.

In a preferred embodiment of the present invention, the base is made of metal.

  In a preferred embodiment of the present invention, the fixing member is fixed to the base with a bolt.

  In a preferred embodiment of the present invention, the fixing member includes an annular portion in which the through hole is formed and a flange portion extending outward from the annular portion.

  In a preferred embodiment of the present invention, a fixing hole through which the bolt is inserted is formed in the flange portion.

  In a preferred embodiment of the present invention, the annular portion has a portion located on the surface side of the intake plate with respect to the bolt in the thickness direction of the intake plate.

  In a preferred embodiment of the present invention, the base has a bottom surface facing the back surface of the intake plate.

  In a preferred embodiment of the present invention, a suction hole is formed in the bottom surface.

  In a preferred embodiment of the present invention, the intake plate is recessed from the back surface and has a recess that overlaps the suction hole when viewed in the thickness direction.

  In a preferred embodiment of the present invention, the plurality of suction holes are arranged in a circle, and the recess is an annular groove.

  A wafer polishing apparatus provided by the second aspect of the present invention includes a suction holding apparatus provided by the first aspect of the present invention, a polishing means for polishing the semiconductor wafer sucked and held by the suction holding apparatus, It is characterized by having.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is a perspective view which shows the suction holding | maintenance apparatus based on 1st Embodiment of this invention. It is a top view which shows the suction holding | maintenance apparatus of FIG. It is sectional drawing which follows the III-III line of FIG. It is a disassembled sectional view which shows the suction holding | maintenance apparatus of FIG. It is a top view which shows the base of the suction holding | maintenance apparatus of FIG. It is principal part sectional drawing which shows an example of the wafer grinding | polishing apparatus using the suction holding | maintenance apparatus of FIG. It is sectional drawing which shows the suction holding | maintenance apparatus based on 2nd Embodiment of this invention. It is a disassembled sectional view which shows the suction holding | maintenance apparatus of FIG. It is sectional drawing which shows the suction holding | maintenance apparatus based on 3rd Embodiment of this invention. It is a top view which shows the suction holding | maintenance apparatus based on 4th Embodiment of this invention. It is sectional drawing which follows the XI-XI line of FIG.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 to 4 show a suction holding device according to a first embodiment of the present invention. The suction holding device A1 of this embodiment includes a base 1, a fixing member 2, and an intake plate 3. The suction holding device A1 is used, for example, for holding the semiconductor wafer 5 in the wafer polishing device B shown in FIG. FIG. 1 is a perspective view of the suction holding device A1. FIG. 2 is a plan view of the suction holding device A1. FIG. 3 is a cross-sectional view of the suction holding device A1 along the line III-III in FIG. 2, and FIG. 4 is an exploded cross-sectional view. FIG. 5 is a plan view of the base 1.

  The base 1 supports the fixing member 2 and the intake plate 3. The base 1 is preferably made of metal. In the present embodiment, the base 1 is made of, for example, stainless steel. The base 1 has a circular shape in plan view as a whole, and is formed with a recess 11. The concave portion 11 has a circular shape with a relatively shallow depth, and has a bottom surface 12. As shown in FIG. 5, the bottom surface 12 is circular.

  The bottom surface 12 is provided with a plurality of suction holes 13. The plurality of suction holes 13 open to the bottom surface 12 and penetrate the base 1 in the present embodiment. The plurality of suction holes 13 are connected to a suction source (not shown) such as a pump via a hose or pipe and a valve. When the suction source is driven, the plurality of suction holes exhibit a suction force. The plurality of suction holes 13 may also be used as discharge holes for discharging a fluid represented by a gas such as air or a liquid such as water from all or any of them. In the present embodiment, the plurality of suction holes 13 are arranged along a plurality of concentric circles. A bolt hole is formed near the outer edge of the bottom surface 12.

  The fixing member 2 is for fixing the intake plate 3 to the base 1, and is attached to the concave portion 11 of the base 1 together with the intake plate 3. In the present embodiment, the fixing member 2 has an annular shape as a whole, and is made of, for example, ceramic that does not have air permeability. The fixing member 2 includes an annular portion 21 and a flange portion 22.

  The annular portion 21 is an annular portion located relatively inside, and a through hole 23 is formed. The through hole 23 has the intake plate 3 disposed therein. The through hole 23 has an end edge 23a. The end edge 23a is an end edge of a portion of the through hole 23 that opens to the side opposite to the base 1, and has a circular shape in the present embodiment. The through-hole 23 has an opening having an end edge 23a (upper opening in the drawing in FIG. 3) smaller in diameter than an opening on the base 1 side (lower opening in the drawing in FIG. 3). That is, the end edge 23a is located radially inward from the end edge of the through hole 23 located on the base 1 side. With such a configuration, the fixing member 2 has the eaves portion 24 formed therein. In the present embodiment, the eaves portion 24 is formed over the entire circumference of the annular portion 21 of the fixing member 2. In addition, the inner surface of the through hole 23 is an inclined surface 25 in the present embodiment.

  The flange portion 22 is a portion extending radially outward from the annular portion 21 and has an annular shape. In the present embodiment, the bottom surface of the flange portion 22 and the bottom surface of the annular portion 21 are flush with each other, and the annular portion 21 is higher than the flange portion 22 as shown in FIG. . The flange portion 22 has a plurality of fixing holes 22a. The plurality of fixing holes 22a pass through the flange portion 22, and are arranged so as to coincide with the plurality of bolt holes of the base 1 shown in FIG.

  The fixing member 2 is attached to the base 1 with a plurality of bolts 28. Each bolt 28 is inserted into the fixing hole 22 a of the flange portion 22 and screwed into the bolt hole provided in the bottom surface 12 of the base 1. In the present embodiment, a cover plate 27 is provided on the upper surface of the flange portion 22 of the fixing member 2. The cover plate 27 is an annular member made of, for example, a metal such as stainless steel, and is for preventing an excessive force from acting on the flange portion 22 from the bolt 28. In the present embodiment, as shown in FIG. 3, the annular portion 21 of the fixing member 2 protrudes upward from the bolt 28. That is, the upper end portion of the annular portion 21 is a portion located on the surface 31 side to be described later of the intake plate 3 with respect to the bolt 28 in the thickness direction of the intake plate 3.

  The suction plate 3 is a member that exerts a suction force for holding a suction holding object such as a semiconductor wafer and is made of a material having air permeability. In the present embodiment, the entire intake plate 3 has a disk shape made of, for example, porous ceramics, and has a front surface 31, a back surface 32, an inclined surface 33 a, and an overhang portion 34.

  The front surface 31 and the back surface 32 face in opposite directions in the thickness direction of the intake plate 3. The back surface 32 faces the bottom surface 12 of the base 1. In the present embodiment, the back surface 32 is in contact with the bottom surface 12 or appropriately bonded to an appropriate position on the bottom surface 12 with an adhesive (not shown).

  The front surface 31 has an outer edge 31a, and the back surface 32 has an outer edge 32a. The front surface 31 and the back surface 32 have a circular shape whose centers coincide with each other, and the front surface 31 is smaller than the back surface 32. Thereby, the outer edge 32 a of the back surface 32 protrudes outward in the radial direction from the outer edge 31 a of the front surface 31. With such a configuration, the air intake plate 3 is formed with a protruding portion 34 over the entire circumference.

  The inclined surface 33 a connects the outer edge 31 a of the front surface 31 and the outer edge 32 a of the back surface 32, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. As shown in FIG. 3, the inclined surface 33 a has an angle along the inclined surface 25 of the through hole 23 of the fixing member 2.

  When polishing of the semiconductor wafer 5 described later is intended, as shown in FIG. 3, the surface 21 a of the annular portion 21 of the fixing member 2 and the surface 31 of the suction plate 3 are preferably flush with each other. .

  As shown in FIG. 4, in assembling the suction holding device A <b> 1, the intake plate 3 is placed on the base 1, and the fixing member 2 is installed so that the intake plate 3 is positioned in the through hole 23. Then, after the cover plate 27 is placed on the flange portion 22 of the fixing member 2, a plurality of bolts 28 are fastened to the base 1 to fix the fixing member 2 to the base 1. As the fixing member 2 is fixed to the base 1, the intake plate 3 is fixed to the base 1. The back surface 32 of the intake plate 3 and the bottom surface 12 of the base 1 may be appropriately bonded with an adhesive (not shown).

  FIG. 6 shows a wafer polishing apparatus B in which the suction holding apparatus A1 is used. The wafer polishing apparatus B includes a suction holding apparatus A1 and polishing means 4. The polishing means 4 is provided with a grindstone, a polishing pad, or the like at a portion facing the suction holding device A1. In addition, means for supplying a polishing liquid required for polishing may be provided. The polishing means 4 is configured to be rotatable while being pressed against the suction holding device A1. Further, the polishing means 4 can be retracted from directly above the suction holding device A1 to other places outside the figure.

  The wafer polishing apparatus B is an apparatus for polishing the semiconductor wafer 5, for example. The semiconductor wafer 5 has a circular plate shape made of, for example, Si and has a diameter of, for example, about 4 inches to 8 inches. By undergoing polishing by the wafer polishing apparatus B, the semiconductor wafer 5 is finished to a thickness of about 600 μm, for example, to a thickness of about 50 to 200 μm, for example.

  By driving the pump as the suction source described above, air is sucked from various places of the suction plate 3 through the plurality of suction holes 13 of the base 1. The semiconductor wafer 5 is sucked and held by the suction force generated thereby. When the semiconductor wafer 5 is placed on the suction holding device A1, it is preferable that the outer edge of the semiconductor wafer 5 overlaps the surface 21a of the annular portion 21 of the fixing member 2. Thereby, the suction force from the intake plate 3 can be effectively applied. Then, the polishing means 4 is rotated while being pressed against the semiconductor wafer 5. Thereby, the semiconductor wafer 5 is polished.

  Next, operations of the suction holding device A1 and the wafer polishing device B will be described.

  Since the protruding portion 34 is formed on the intake plate 3 and the eaves portion 24 is formed on the fixing member 2, the intake plate 3 disposed in the through hole 23 is fixed to the base 1 by the fixing member 2. can do. For this reason, in order to fix the intake plate 3 to the base 1, it is not essential to use an adhesive, for example. Further, when the suction plate 3 and the base 1 are bonded using an adhesive, even if the adhesive is deteriorated, the suction plate 3 is not likely to be unfairly lifted from the base 1. Therefore, the intake plate 3 can be more securely fixed to the base 1. Furthermore, in the wafer polishing apparatus B, for example, the semiconductor wafer 5 can be appropriately held in a flat state. By holding the semiconductor wafer 5 appropriately, polishing by the polishing means 4 can be performed more precisely. Therefore, the thickness of the semiconductor wafer 5 can be adjusted to a desired thickness and finished with a good surface roughness.

  Since the suction plate 3 is made of porous ceramics and the fixing member 2 is made of non-breathable ceramics, the suction plate 3 and the fixing member 2 are relatively advanced by polishing by the polishing means 4. It can be expected to be polished. The structure in which the surface 31 of the suction plate 3 and the surface 21a of the annular portion 21 of the fixing member 2 are flush with each other can make the suction by the suction plate 3 more effective while holding the semiconductor wafer 5 flat. Is suitable. The state in which the surface 31 of the intake plate 3 and the surface 21a of the annular portion 21 of the fixing member 2 are flush with each other by polishing the intake plate 3 and the fixing member 2 at a relatively similar degree of progress. Can be maintained over time.

  An inclined surface 33 a is formed in the projecting portion 34 of the intake plate 3, and an inclined surface 25 is formed in the through hole 23 of the fixing member 2, whereby the projecting portion 34 of the intake plate 3 is formed by the eaves portion 24 of the fixing member 2. It is possible to reliably hold the air intake, which is preferable for fixing the intake plate 3.

  The overhanging portion 34 of the intake plate 3 is provided on the entire circumference of the intake plate 3, and the eaves portion 24 of the fixing member 2 is provided on the entire periphery of the fixing member 2. It is possible to hold down. This is suitable for more reliable fixing of the intake plate 3.

  Since the base 1 is made of metal and the fixing member 2 is fixed to the base 1 with bolts 28, the fixing member 2 can be firmly fixed to the base 1. By providing the cover plate 27, it is possible to avoid that the fastening force of the bolt 28 is locally excessively applied to the fixing member 2, and damage to the fixing member 2 can be prevented. .

  Since the annular portion 21 has a portion located on the surface 31 side of the intake plate 3 with respect to the bolt 28 in the thickness direction of the intake plate 3, it is possible to prevent the bolt 28 from inhibiting the polishing of the polishing means 4. it can.

  The suction plate 3 is formed with a recess 36 that overlaps the suction hole 13 when viewed in the thickness direction, so that a wider portion of the suction plate 3 can be sucked from the suction hole 13. In order to ensure the fixing of the intake plate 3 provided with the inclined surface 33a, it is preferable to increase the thickness of the intake plate 3 to some extent. When the suction plate 3 becomes thick, the suction resistance increases, and it is difficult to suck the suction plate 13 uniformly. The recess 36 is suitable for solving such problems and realizing uniform suction.

  The configuration in which the plurality of suction holes 13 are arranged in a circular shape and the recess 36 is an annular groove is suitable for holding the circular semiconductor wafer 5 with a uniform suction force, for example.

  7 to 11 show other embodiments of the present invention. In these drawings, the same or similar elements as those in the above embodiment are denoted by the same reference numerals as those in the above embodiment.

  7 and 8 show a suction holding device according to the second embodiment of the present invention. The suction holding device A2 of the present embodiment is mainly different from the above-described embodiment in the configuration of the intake plate 3. FIG. 7 is a sectional view of the suction holding device A2, and FIG. 8 is an exploded sectional view of the suction holding device A2.

  In the present embodiment, the intake plate 3 is constituted by a plurality of annular elements 3A, 3B, 3C, 3D and a trapezoidal element 3E. The centers of the plurality of annular elements 3A, 3B, 3C, 3D and the frustum-shaped element 3E coincide with each other. In the present embodiment, each of the plurality of annular elements 3A, 3B, 3C, 3D is an annular ring. It is made into a shape. The annular elements 3A and 3C and the frustum-shaped element 3E are made of a material having relatively high air permeability such as porous ceramics having a relatively high porosity, and the annular elements 3A and 3C are highly air permeable as referred to in the present invention. Corresponds to an annular element. The annular elements 3B and 3D are made of a material having a relatively low air permeability such as a porous ceramic having a relatively low porosity or a ceramic having no air permeability, and correspond to the low air permeability annular element referred to in the present invention. . The annular elements 3A and 3C and the frustum-shaped element 3E corresponding to the high air permeability annular elements and the annular elements 3B and 3D corresponding to the low air permeability annular elements are alternately arranged. In addition, the annular elements 3A, 3B, 3C, 3D and the trapezoidal element 3E have the same size in the vertical direction (thickness direction) in the figure.

  The annular element 3A has a front surface 31A, a back surface 32A, an inclined surface 33Aa, an inclined surface 33Ab, an overhang portion 34A, and an eaves portion 35A. The front surface 31A and the back surface 32A face in opposite directions to each other in the thickness direction of the annular element 3A (intake plate 3). The back surface 32A faces the bottom surface 12 of the base 1, and in the present embodiment, the back surface 32A is in contact with the bottom surface 12 or appropriately bonded to an appropriate position on the bottom surface 12 with an adhesive (not shown).

  The front surface 31A has an outer edge 31Aa and an inner edge 31Ab, and the back surface 32A has an outer edge 32Aa and an inner edge 32Ab. The front surface 31A and the back surface 32A have an annular shape whose centers coincide with each other, and the front surface 31A is smaller than the back surface 32B. That is, the outer edge 32Aa of the back surface 32A is located radially outward from the outer edge 31Aa of the front surface 31A. With such a configuration, the annular element 3A is formed with an overhanging portion 34A over the entire circumference. Further, the inner edge 31Ab of the front surface 31A is located radially inward from the inner edge 32Ab of the back surface 32A. With such a configuration, the annular element 3A has the eaves portion 35A formed over the entire circumference.

  The inclined surface 33Aa connects the outer edge 31Aa of the front surface 31A and the outer edge 32Aa of the rear surface 32A, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. The inclined surface 33Ab connects the inner edge 31Ab of the front surface 31A and the inner edge 32Ab of the rear surface 32A, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. The inclined surface 33Aa and the inclined surface 33Ab are substantially parallel to each other.

  The annular element 3B has a front surface 31B, a back surface 32B, an inclined surface 33Ba, an inclined surface 33Bb, an overhang portion 34B, and an eaves portion 35B. The front surface 31B and the back surface 32B face in opposite directions to each other in the thickness direction of the annular element 3B (intake plate 3). The back surface 32B faces the bottom surface 12 of the base 1, and in this embodiment, the back surface 32B is in contact with the bottom surface 12 or is appropriately bonded to an appropriate position on the bottom surface 12 with an adhesive (not shown).

  The front surface 31B has an outer edge 31Ba and an inner edge 31Bb, and the back surface 32B has an outer edge 32Ba and an inner edge 32Bb. The front surface 31B and the back surface 32B have an annular shape whose centers coincide with each other, and the front surface 31B is smaller than the back surface 32B. That is, the outer edge 32Ba of the back surface 32B is located radially outward from the outer edge 31Ba of the front surface 31B. With such a configuration, the annular element 3B is formed with a protruding portion 34B over the entire circumference. Further, the inner edge 31Bb of the front surface 31B is located radially inward from the inner edge 32Bb of the back surface 32B. With such a configuration, the annular element 3B is formed with the eaves portion 35B over the entire circumference.

  The inclined surface 33Ba connects the outer edge 31Ba of the front surface 31B and the outer edge 32Ba of the back surface 32B, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. The inclined surface 33Bb connects the inner edge 31Bb of the front surface 31B and the inner edge 32Bb of the back surface 32B, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. The inclined surface 33Ba and the inclined surface 33Bb are substantially parallel to each other.

  The annular element 3C has a front surface 31C, a back surface 32C, an inclined surface 33Ca, an inclined surface 33Cb, an overhang portion 34C, and an eaves portion 35C. The front surface 31C and the back surface 32C face in opposite directions to each other in the thickness direction of the annular element 3C (intake plate 3). The back surface 32C faces the bottom surface 12 of the base 1, and in the present embodiment, the back surface 32C is in contact with the bottom surface 12 or appropriately bonded to an appropriate position on the bottom surface 12 with an adhesive (not shown).

  The front surface 31C has an outer edge 31Ca and an inner edge 31Cb, and the back surface 32C has an outer edge 32Ca and an inner edge 32Cb. The front surface 31C and the back surface 32C have an annular shape whose centers coincide with each other, and the front surface 31C is smaller than the back surface 32B. That is, the outer edge 32Ca of the back surface 32C is located radially outward from the outer edge 31Ca of the front surface 31C. With such a configuration, the annular element 3C is formed with an overhanging portion 34C over the entire circumference. Further, the inner edge 31Cb of the front surface 31C is located radially inward from the inner edge 32Cb of the back surface 32C. With such a configuration, the annular element 3 </ b> C has the eaves portion 35 </ b> C formed over the entire circumference.

  The inclined surface 33Ca connects the outer edge 31Ca of the front surface 31C and the outer edge 32Ca of the back surface 32C, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. The inclined surface 33Cb connects the inner edge 31Cb of the front surface 31C and the inner edge 32Cb of the back surface 32C, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. The inclined surface 33Ca and the inclined surface 33Cb are substantially parallel to each other.

  The annular element 3D has a front surface 31D, a back surface 32D, an inclined surface 33Da, an inclined surface 33Db, an overhang portion 34D, and an eaves portion 35D. The front surface 31D and the back surface 32D face in opposite directions in the thickness direction of the annular element 3D (intake plate 3). The back surface 32D faces the bottom surface 12 of the base 1, and in this embodiment, the back surface 32D is in contact with the bottom surface 12 or is appropriately bonded to an appropriate position on the bottom surface 12 with an adhesive (not shown).

  The front surface 31D has an outer edge 31Da and an inner edge 31Db, and the back surface 32D has an outer edge 32Da and an inner edge 32Db. The front surface 31D and the back surface 32D have an annular shape whose centers coincide with each other, and the front surface 31D is smaller than the back surface 32D. That is, the outer edge 32Da of the back surface 32D is located radially outward from the outer edge 31Da of the front surface 31D. With this configuration, the annular element 3D is formed with an overhanging portion 34D over the entire circumference. Further, the inner edge 31Db of the front surface 31D is located radially inward from the inner edge 32Db of the back surface 32D. With such a configuration, the annular element 3D has the eaves portion 35D formed over the entire circumference.

  The inclined surface 33Da connects the outer edge 31Da of the front surface 31D and the outer edge 32Da of the back surface 32D, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. The inclined surface 33Db connects the inner edge 31Db of the front surface 31D and the inner edge 32Db of the back surface 32D, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3. The inclined surface 33Da and the inclined surface 33Db are substantially parallel to each other.

  The frustum-shaped element 3E has a front surface 31E, a back surface 32E, an inclined surface 33Ea, and an overhang portion 34E. The front surface 31E and the back surface 32E face in opposite directions to each other in the thickness direction of the frustum-shaped element 3E (intake plate 3). The back surface 32E faces the bottom surface 12 of the base 1, and in this embodiment, the back surface 32E is in contact with the bottom surface 12 or is appropriately bonded to an appropriate position on the bottom surface 12 with an adhesive (not shown).

  The front surface 31E has an outer edge 31Ea, and the back surface 32E has an outer edge 32Ea. The front surface 31E and the back surface 32E have a circular shape whose centers coincide with each other, and the front surface 31E is smaller than the back surface 32B. That is, the outer edge 32Ea of the back surface 32E is located radially outward from the outer edge 31Ea of the front surface 31E. With such a configuration, the frustum-shaped element 3E has a protruding portion 34E formed over the entire circumference.

  The inclined surface 33Ea connects the outer edge 31Ea of the front surface 31E and the outer edge 32Ea of the back surface 32E, and is a smooth surface inclined with respect to the thickness direction of the intake plate 3.

  In the present embodiment, the radial dimensions of the annular elements 3B and 3D corresponding to the low air permeability annular elements are significantly smaller than the annular elements 3A and 3C corresponding to the high air permeability annular elements. Moreover, the radius of the frustum-shaped element 3E is significantly larger than the radial dimension of the annular elements 3B and 3D. With such a configuration, the annular elements 3B and 3D function as a blocking wall that blocks ventilation. On the other hand, a plurality of recesses 36 are formed in the annular elements 3A and 3C and the trapezoidal element 3E that are intended for positive ventilation. Each recess 36 is formed as an annular groove in the same manner as in the above-described embodiment, and has a shape, size, and arrangement that overlap each other when the suction hole 13 of the base 1 and the intake plate 3 are viewed in the thickness direction. ing.

  As shown in FIG. 8, in assembling the suction holding device A2, the trapezoidal element 3E, the annular element 3D, the annular element 3C, the annular element 3B, and the annular element 3A are placed on the base 1 in the order of concentric circles. To do. The inclined surface 33Ea of the frustum-shaped element 3E and the inclined surface 33Db of the annular element 3D are parallel to each other and have substantially the same diameter. Thereby, the inclined surface 33Ea of the trapezoidal element 3E and the inclined surface 33Db of the annular element 3D abut. The inclined surface 33Da of the annular element 3D and the inclined surface 33Cb of the annular element 3C are parallel to each other and have substantially the same diameter. Thereby, the inclined surface 33Da of the annular element 3D and the inclined surface 33Cb of the annular element 3C abut. Further, the inclined surface 33Ca of the annular element 3C and the inclined surface 33Bb of the annular element 3B are parallel to each other and have substantially the same diameter. Thereby, the inclined surface 33Ca of the annular element 3C abuts on the inclined surface 33Bb of the annular element 3B. Further, the inclined surface 33Ba of the annular element 3B and the inclined surface 33Ab of the annular element 3A are parallel to each other and have substantially the same diameter. Thereby, the inclined surface 33Ba of the annular element 3B and the inclined surface 33Ab of the annular element 3A abut.

  Then, the fixing member 2 is installed so that the intake plate 3 constituted by the plurality of annular elements 3A, 3B, 3C, 3D and the trapezoidal element 3E is positioned in the through hole 23. The inclined surface 33Aa of the annular element 3A and the inclined surface 25 of the fixing member 2 are parallel to each other and have substantially the same diameter. Thereby, the inclined surface 33Aa of the annular element 3A and the inclined surface 25 of the fixing member 2 come into contact with each other.

  Next, after the cover plate 27 is placed on the flange portion 22 of the fixing member 2, a plurality of bolts 28 are fastened to the base 1 to fix the fixing member 2 to the base 1. Along with the fixing of the fixing member 2 to the base 1, the fastening force of the bolt 28 is passed through the fixing member 2 to the annular element 3A, the annular element 3B, the annular element 3C, the annular element 3D, and the frustum-shaped element 3E. Communicated. Thereby, the intake plate 3 is fixed to the base 1. The back surface 32 of the intake plate 3 and the bottom surface 12 of the base 1 may be appropriately bonded with an adhesive (not shown).

  Moreover, in this embodiment, the several suction hole 13 of the base 1 is divided into three groups, and is connected to the pump as the suction source mentioned above. These groups are configured by a suction hole 13 that overlaps the recess 36 of the annular element 3A, a suction hole 13 that overlaps the recess 36 of the annular element 3C, and a suction hole 13 that overlaps the recess 36 of the trapezoidal element 3E. The plurality of suction holes 13 can selectively exert suction force for each of these groups, for example, by controlling the opening and closing of the illustrated valve.

  According to such an embodiment, by controlling the opening and closing of the valve described above, for example, a mode in which only the frustum-shaped element 3E exerts a suction force, and only a frustum-shaped element 3E and an annular element 3C exhibit a suction force. The mode and the mode in which all of the annular elements 3A and 3C and the frustum element 3E exhibit a suction force can be appropriately used. Thereby, for example, the suction area can be set according to the semiconductor wafer 5 having a diameter different from 4 inches to 8 inches. Therefore, a plurality of semiconductor wafers 5 having different sizes can be appropriately held.

  The annular elements 3B and 3D configured as low-breathing annular elements function as so-called blocking walls. Thereby, in the generation | occurrence | production of the selective suction force mentioned above, a suction force can be exhibited in the area | region which should not generate | occur | produce a suction force, and the fall of the suction force in the area | region which should be attracted | sucked can be prevented. In order to realize effective suction, a configuration in which the edge of the semiconductor wafer 5 to be held overlaps with the annular elements 3B and 3D or the fixing member 2 configured as a low air permeability annular element is preferable.

  The plurality of annular elements 3A, 3B, 3C, 3D and the trapezoidal element 3E are configured to transmit the fastening force of the fixing member 2 to each other. For this reason, a plurality of elements formed as separate bodies, ie, the plurality of annular elements 3A, 3B, 3C, 3D and the frustum-shaped element 3E, are fixed together by fixing the fixing member 2 as one member to the base 1. It can be fixed to the base 1.

  FIG. 9 shows a suction holding device according to a third embodiment of the present invention. The suction holding device A3 of the present embodiment has the same configuration as the suction holding device A1 described above except that the configuration of the fixing member 2 and the suction plate 3 is slightly different.

  In the present embodiment, a step 23 c is formed in the through hole 23 of the fixing member 2. The step 23c is a portion that connects a surface extending along the thickness direction of the intake plate 3 from the end edge 23a of the through hole 23 and a surface extending along the thickness direction from the edge opposite to the end edge 23a. In the present embodiment, it is provided over the entire circumference of the through hole 23. Also in the fixing member 2 having such a configuration, an eaves portion 24 is formed.

  A step 33 c is formed in the intake plate 3. The step 33c is a part connecting a surface extending along the thickness direction from the outer edge 31a of the front surface 31 and a surface extending along the thickness direction from the outer edge 32a of the back surface 32. In the present embodiment, the step plate 33c It is provided all around. The overhanging portion 34 is also formed in the intake plate 3 having such a configuration.

  When the fixing member 2 and the intake plate 3 are attached to the base 1, the step 23c of the fixing member 2 and the step 33c of the intake plate 3 are engaged with each other, and preferably come into contact with each other.

  Also according to such an embodiment, the intake plate 3 can be appropriately fixed to the base 1. Further, as can be understood from the present embodiment, the structure having a step in the present invention is applied to all of the fixing member 2, the annular elements 3A, 3B, 3C, 3D and the frustum-shaped element 3E of the suction holding device A2, or You may use it combining in any selected suitably.

  10 and 11 show a suction holding device according to a fourth embodiment of the present invention. 10 is a plan view of the suction holding device A4 of the present embodiment, and FIG. 11 is a cross-sectional view taken along the line XI-XI of FIG. Note that the configuration of the suction holding device A4 in the cross-sectional view taken along the line III'-III 'of FIG. 10 substantially conforms to the configuration of the suction holding device A1 shown in FIG.

  In the present embodiment, as shown in FIG. 10, the two eaves portions 24 are formed on the fixing member 2, and the two overhang portions 34 are formed on the intake plate 3. The two eaves portions 24 are spaced apart from each other in the circumferential direction. Further, the two overhanging portions 34 are also spaced apart in the circumferential direction. The circumferential positions and the circumferential dimensions of the two eaves portions 24 and the two overhang portions 34 are substantially the same. Each eaves portion 24 and each overhang portion 34 have a size that occupies a range of approximately 90 ° in the circumferential direction. The interval between the two eaves portions 24 and the interval between the two overhang portions 34 are both about 90 ° in the circumferential direction.

  The inclined surface 25 or the step 23 c described above is formed at a portion corresponding to the eaves portion 24 of the fixing member 2. Correspondingly, the inclined surface 33a or the step 33c described above is formed in a portion corresponding to the protruding portion 34 of the intake plate 3.

  As shown in FIG. 11, an upright side surface 26 is formed at a portion of the through hole 23 of the fixing member 2 sandwiched between the two eaves portions 24. The standing side surface 26 is a surface that stands up along the thickness direction of the intake plate 3 and has a partial cylindrical shape. Further, an upright side surface 37 is formed at a portion of the intake plate 3 sandwiched between the two overhang portions 34. The standing side surface 37 is a surface that stands up along the thickness direction of the intake plate 3 and has a partial cylindrical shape. The standing side surface 26 of the fixing member 2 and the standing side surface 37 of the intake plate 3 are parallel to each other and have substantially the same diameter.

  Also according to such an embodiment, the intake plate 3 can be appropriately fixed to the base 1. Further, the fixing member 2 and the intake plate 3 do not have a uniform shape or configuration in the circumferential direction, and have discontinuous portions in the circumferential direction. By providing this discontinuous portion, it is possible to prevent the intake plate 3 from rotating unfairly with respect to the base 1.

  The suction holding apparatus and wafer polishing apparatus according to the present invention are not limited to the above-described embodiments. The specific configuration of each part of the suction holding apparatus and the wafer polishing apparatus according to the present invention can be varied in design in various ways.

  The base, the fixing member, and the intake plate referred to in the present invention are not limited to a circular shape or an annular shape, and may be configured in, for example, a substantially polygonal shape or a substantially polygonal annular shape. The suction holding device according to the present invention is suitable for being used for holding a semiconductor wafer in a wafer polishing apparatus, but its use is not limited to this, and it may be used for a purpose of holding an object using suction. it can.

A1 to A3 Suction holding device B Wafer polishing device 1 Base 11 Recess 12 Bottom surface 13 Suction hole 2 Fixing member 21 Annular portion 21a Surface 22 Flange portion 22a Fixing hole 23 Through hole 23a Edge 23c Step 24 Eaves portion 25 Inclined surface 26 Standing Side surface 27 Cover plate 28 Bolt 3 Suction plate 34 Overhang portion 31 Surface 31a Outer edge 32 Back surface 32a Outer edge 33a Inclined surface 33c Step 3A-3D Annular element 3E Frustum element 31A-31E 32Aa to 32Ea Outer edge 32Ab to 32Db Inner edge 33Aa to 33Ea Inclined surface 33Ab to 33Db Inclined surface 34A to 34E Overhang portion 35A to 35D Eave portion 36 Recessed portion 36 Recessed side 4 Polishing means 4 Semiconductor wafer

Claims (19)

An air intake plate made of a material having air permeability and having a front surface and a back surface facing opposite to each other;
A fixing member having a through hole, and the intake plate is disposed in the through hole;
A base to which the fixing member is attached and located on the back side of the intake plate;
The intake plate has a projecting portion in which the outer edge of the back surface projects outward from the outer edge of the front surface,
The fixing member has an eaves portion in which an end edge of the through hole located on the side opposite to the base is positioned inwardly from an outer edge of the back surface of the projecting portion in the thickness direction of the intake plate. ,
The base has a bottom surface facing the back surface of the intake plate,
A suction hole is formed on the bottom surface,
The suction holding device according to claim 1, wherein the suction plate is recessed from the back surface thereof and has a recess that encloses the suction hole as viewed in the thickness direction. The plurality of suction holes are arranged in a circle,
The suction holding device according to claim 1, wherein the recess is an annular groove. A plurality of the suction holes are arranged in a plurality of concentric rows,
The suction holding device according to claim 2, wherein the number of the plurality of suction holes is larger in the outer row.   The suction holding device according to claim 1, wherein at least a part of the intake plate is made of porous ceramics.   The suction holding device according to claim 4, wherein the fixing member is made of ceramics having no air permeability.   The suction holding device according to claim 1, wherein the fixing member has a surface that is flush with the surface of the intake plate.   The suction holding device according to any one of claims 1 to 6, wherein the projecting portion of the intake plate has an inclined surface that connects the outer edge of the front surface and the outer edge of the rear surface.   The suction holding device according to claim 1, wherein the protruding portion of the intake plate has a step located between the outer edge of the front surface and the outer edge of the rear surface.   The suction according to claim 1, wherein the protruding portion of the intake plate is provided on the entire circumference of the intake plate, and the eaves portion of the fixing member is provided on the entire periphery of the fixing member. Holding device.   The suction holding device according to any one of claims 1 to 8, wherein the two protruding portions of the intake plate are provided apart from each other, and the two eaves portions of the fixing member are provided apart from each other. .   The intake plate is sandwiched between the two projecting portions and has an upstanding side surface that stands up along the thickness direction of the intake plate, and the fixing member is sandwiched between the two eaves portions, and the intake air The suction holding device according to claim 10, wherein the suction holding device has an upstanding side surface that stands up along a thickness direction of the plate. The intake plate is composed of a plurality of annular elements whose centers coincide with each other,
Each of the annular elements has an overhanging portion in which an outer edge of the back surface protrudes outward from an outer edge of the surface, and an eaves portion in which an inner edge of the surface is located inward of an inner edge of the back surface. The suction holding device according to any one of 1 to 11.   The plurality of annular elements include a highly air permeable annular element having a relatively high air permeability and a low air permeable annular element having a relatively low air permeability, and the high air permeable annular element and the low air permeable annular element comprise The suction holding device according to claim 10 arranged alternately.   The suction holding device according to claim 1, wherein the base is made of metal.   The suction holding device according to claim 14, wherein the fixing member is fixed to the base by a bolt.   The suction holding device according to claim 15, wherein the fixing member includes an annular portion in which the through-hole is formed and a flange portion extending outward from the annular portion.   The suction holding device according to claim 16, wherein a fixing hole through which the bolt is inserted is formed in the flange portion.   The suction holding device according to claim 17, wherein the annular portion has a portion located on the surface side of the intake plate with respect to the bolt in the thickness direction of the intake plate. A suction holding device according to any one of claims 1 to 18,
Polishing means for polishing the semiconductor wafer sucked and held by the suction holding device;
A wafer polishing apparatus comprising:

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