Elastic membrane and its mounting structure

Abstract

To provide an elastic membrane which is easily bonded to a polishing head.SOLUTION: An elastic membrane 10 is attached to a polishing head of a CMP device and used for wafer holding. The elastic membrane 10 comprises: a silicone rubber layer 111 with a wafer holding surface 111a; and a tabular reinforcement material 112 formed of a non-silicone material and laminated on an opposite side of the wafer holding surface 111a of the silicone rubber layer 111. The reinforcement material 112 is exposed to a site 14 to be bonded to the polishing head on a polishing head attachment side.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present invention relates to an elastic membrane that is attached to a polishing head of a CMP apparatus and used to hold a wafer, and to an attachment structure thereof. [Background technology]

[0002] An elastic membrane used to hold a wafer is attached to the polishing head of a CMP device. Patent Document 1 discloses such an elastic membrane that includes an inner rubber layer on the polishing head attachment side, an outer rubber layer on the wafer holding side, and an intermediate rigid layer therebetween. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-122896 Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an elastic membrane that is easily adhered to a polishing head. [Means for solving the problem]

[0005] The present invention provides an elastic membrane that is attached to a polishing head of a CMP apparatus and used to hold a wafer, the elastic membrane comprising: a silicone rubber layer having a wafer holding surface; and a plate-shaped reinforcing member formed of a non-silicone material laminated on the side of the silicone rubber layer opposite to the wafer holding surface, a bottomed hole is formed on the silicone rubber layer on the opposite side to the wafer support surface, and the reinforcing member is fitted into the bottomed hole of the silicone rubber layer; The reinforcing material is exposed at a portion to be bonded to the polishing head on the polishing head mounting side.

[0006] The present invention relates to an attachment structure for the elastic membrane of the present invention to a polishing head of a CMP apparatus, in which the reinforcing material exposed to the intended bonding portion of the elastic membrane is bonded to the polishing head via an adhesive layer. Effect of the Invention

[0007] According to the present invention, the reinforcing material is formed from a non-silicone material and is relatively easy to adhere, and is exposed at the portion intended to be adhered to the polishing head on the polishing head mounting side, so that it can be easily adhered to the polishing head. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 2 is a perspective view of an elastic membrane according to the first embodiment. [Figure 1B] FIG. 2 is a cross-sectional perspective view of an elastic membrane according to the first embodiment. [Diagram 2] 3 is a cross-sectional view showing a mounting structure of the elastic film to a polishing head of a CMP apparatus according to the first embodiment. FIG. [Diagram 3] 10 is a cross-sectional perspective view of a modified example of the elastic membrane according to the first embodiment. FIG. [Figure 4] FIG. 11 is a cross-sectional perspective view of an elastic membrane according to a second embodiment. [Diagram 5] 11 is a cross-sectional view showing a mounting structure of an elastic film to a polishing head of a CMP apparatus according to a second embodiment. FIG. [Figure 6] FIG. 11 is a cross-sectional perspective view of an elastic membrane according to a third embodiment. [Figure 7] 11 is a cross-sectional view showing a mounting structure of an elastic film to a polishing head of a CMP apparatus according to a third embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The embodiments will be described in detail below.

[0010] (Embodiment 1) 1A and 1B show an elastic membrane 10 according to embodiment 1. This elastic membrane 10 is attached to the polishing head of a CMP device and is used to hold a semiconductor wafer that is polished by pressing it against a polishing pad. In the following description, the side where the polishing head is attached is referred to as "upper" and the side where the wafer is held is referred to as "lower."

[0011] The elastic membrane 10 according to the first embodiment is formed in a shallow circular dish shape having a disk-shaped membrane body 11, a cylindrical tubular portion 12 integrally provided so as to extend upwardly in continuation from the periphery of the membrane body 11, and an annular portion 13 integrally provided so as to extend inward in continuation from the upper end of the membrane body 11. The thicknesses of the membrane body 11, the tubular portion 12, and the annular portion 13 are, for example, 0.3 mm or more and 6 mm or less.

[0012] The membrane body 11 comprises a lower silicone rubber layer 111 and an upper plate-shaped reinforcing material 112 .

[0013] Silicone rubber layer 111 is formed in a disk shape, and has wafer holding surface 111a constituted by its flat lower surface. A bottomed disk hole having an inner diameter slightly smaller than the diameter of silicone rubber layer 111 is formed in the upper surface of silicone rubber layer 111. The thickness of the portion of silicone rubber layer 111 where the bottomed disk hole is formed is, for example, 0.1 mm or more and 2 mm or less. Silicone rubber layer 111 is formed of crosslinked silicone rubber.

[0014] Reinforcing material 112 is formed in a disk shape with flat upper and lower surfaces having the same shape as the bottomed disk hole of silicone rubber layer 111, and is fitted into the bottomed disk hole. In this way, reinforcing material 112 is laminated on the side opposite to wafer holding surface 111a of silicone rubber layer 111. Reinforcing material 112 may be adhered to silicone rubber layer 111.

[0015] The reinforcing material 112 is formed of a non-silicone material that is easily adhesive and has a smaller contact angle with water or a solvent than silicone rubber. Examples of materials forming the reinforcing material 112 include resins and metals. Examples of resins include thermoplastic resins such as polyether ether ketone resin (PEEK) and polyethylene terephthalate resin (PET); and thermosetting resins such as phenolic resin and epoxy resin. When the reinforcing material 112 is formed of resin, its hardness measured with a type D durometer is preferably 10 or more and 95 or less, more preferably 50 or more and 95 or less. This hardness is measured based on JIS K7215-1986. Examples of metals include stainless steel such as SUS304. The reinforcing material 112 may be composed of a composite material of resin and metal.

[0016] The thickness of reinforcing material 112 is, for example, not less than 0.02 mm and not more than 2 mm. The thickness of reinforcing material 112 may be the same as or different from the thickness of the portion of silicone rubber layer 111 where the bottomed disk hole is formed.

[0017] The tubular portion 12 is formed integrally with the silicone rubber layer 111, and the inner peripheral portion of the lower surface thereof abuts and engages with the peripheral portion of the reinforcing material 112 of the membrane body 11, thereby physically fixing the reinforcing material 112. The annular portion 13 is formed integrally with the tubular portion 12. Therefore, the tubular portion 12 and the annular portion 13 are formed of the same crosslinked silicone rubber as the silicone rubber layer 111 of the membrane body 11.

[0018] In the elastic membrane 10 according to the first embodiment, a portion 14 to be bonded to a polishing head is formed in the central portion of the membrane body 11 on the polishing head attachment side as shown by the dashed line in Fig. 1B. In the portion 14 to be bonded, the upper surface of the reinforcing member 112 on the polishing head attachment side is exposed.

[0019] 2 shows a structure 100 for mounting an elastic membrane 10 to a polishing head 20 of a CMP device according to the first embodiment. The polishing head 20 is formed in a cylindrical shape. An annular groove 21 with a U-shaped cross section that opens outward and extends in the circumferential direction is provided on the outer periphery of the tip of the polishing head 20. A plurality of beam-shaped brackets 22 are provided at intervals in the circumferential direction on the inside of the tip of the polishing head 20, each of which extends slightly diagonally downward from the inner wall toward the center. The brackets 22 are joined in the center, and a cylindrical membrane mounting part 23 is provided extending downward from the joint.

[0020] In the mounting structure 100 for mounting the elastic membrane 10 to the polishing head 20 of the CMP device according to the first embodiment, the annular portion 13 of the elastic membrane 10 fits into the annular groove 21 of the polishing head 20 over the entire circumference, and the reinforcing material 112 exposed at the intended bonding portion 14 on the polishing head mounting side of the elastic membrane 10 is bonded to the tip of the membrane mounting portion 23 of the polishing head 20 via an adhesive layer 30. The adhesive layer 30 is made of, for example, a double-sided adhesive tape or a hardened adhesive.

[0021] According to the elastic membrane 10 of the first embodiment having the above configuration, a single sealed space is formed between the elastic membrane 10 and the polishing head 20, but since the membrane body 11 is formed by laminating the reinforcing material 112 on the silicone rubber layer 111 on the wafer holding side, the deformation of the membrane body 11 according to the pressure distribution in the sealed space is reduced, and as a result, the pressing force of the semiconductor wafer against the polishing pad can be made uniform. In addition, since the upper surface of the easily adhesive reinforcing material 112 made of a non-silicone material on the polishing head mounting side is exposed to the portion 14 to be bonded to the polishing head 20, it can be easily bonded to the polishing head 20.

[0022] Since it is sufficient that the reinforcing material 112 is exposed at least in the portion 14 to be bonded to the polishing head 20, as shown in Fig. 3, an outer peripheral side annular rubber layer 15 (rubber layer on the polishing head attachment side) may be provided on the polishing head attachment side so as to cover the outer peripheral part of the upper surface of the reinforcing material 112 on the polishing head attachment side, which is continuous with the lower end of the cylindrical part 12, and sandwich the reinforcing material 112 between the silicone rubber layer 111. The outer peripheral side annular rubber layer 15 is formed of the same crosslinked silicone rubber as the silicone rubber layer 111. The outer peripheral side annular rubber layer 15 enhances the integration of the reinforcing material 112 with the poorly adhesive silicone rubber layer 111, and as a result, a high reinforcing effect of the silicone rubber layer 111 by the reinforcing material 112 can be obtained.

[0023] (Embodiment 2) 4 shows an elastic membrane 10 according to embodiment 2. Note that parts having the same names as those in embodiment 1 are designated by the same reference numerals as those in embodiment 1.

[0024] In the elastic membrane 10 according to the second embodiment, an inner annular rubber layer 16 (rubber layer on the polishing head mounting side) is provided on the polishing head mounting side so as to cover the inner peripheral portion of the membrane body 11 on the polishing head mounting side and sandwich the reinforcing material 112 between the silicone rubber layer 111. The inner annular rubber layer 16 is bonded to the silicone rubber layer 111 via the upper and lower through holes 112a formed in the reinforcing material 112, and is therefore formed of the same crosslinked silicone rubber as the silicone rubber layer 111. The inner annular rubber layer 16 holds the reinforcing material 112 sandwiched between the silicone rubber layer 111 and the inner annular rubber layer 16, and the integrity of the reinforcing material 112 to the poorly adhesive silicone rubber layer 111 is enhanced, so that a high reinforcing effect of the silicone rubber layer 111 by the reinforcing material 112 can be obtained.

[0025] In the elastic membrane 10 according to the second embodiment, a first portion 141 to be attached to the polishing head is formed in the center of the membrane body 11 on the polishing head attachment side. In addition, a plurality of second portions 142 to be attached to the polishing head are formed at intervals in the circumferential direction on the outer side of the inner peripheral side annular rubber layer 16. In both the first portion 141 to be attached and the plurality of second portions 142 to be attached, the upper surface of the reinforcing member 112 on the polishing head attachment side is exposed.

[0026] 5 shows a mounting structure 100 for mounting the elastic membrane 10 to the polishing head 20 of a CMP device according to embodiment 2. The polishing head 20 is provided with a cylindrical first membrane mounting portion 231 extending downward from the joint of the multiple brackets 22, and is also provided with a cylindrical second membrane mounting portion 232 extending downward from the middle portion of each of the multiple brackets 22.

[0027] In the mounting structure 100 for mounting the elastic membrane 10 to the polishing head 20 of the CMP apparatus in embodiment 2, the annular portion 13 of the elastic membrane 10 is fitted into the annular groove 21 of the polishing head 20 around its entire circumference, and the reinforcing material 112 exposed to the first intended bonding portion 141 of the elastic membrane 10 is adhered to the tip of the first membrane mounting portion 231 of the polishing head 20 via a first adhesive layer 301, and the reinforcing material 112 exposed to multiple second intended bonding portions 142 is adhered to the tip of the corresponding second membrane mounting portion 232 of the polishing head 20 via a second adhesive layer 302.

[0028] The other configurations and effects are the same as those of the first embodiment.

[0029] (Embodiment 3) 6 shows an elastic membrane 10 according to embodiment 3. Note that parts having the same names as those in embodiment 1 are designated by the same reference numerals as those in embodiment 1.

[0030] The elastic membrane 10 according to the third embodiment is formed in a disk shape having the same configuration as the membrane body 11 in the first embodiment, and therefore includes a lower silicone rubber layer 111 and an upper plate-shaped reinforcing material 112. A portion 14 to be bonded to the polishing head is formed on the outer periphery of the elastic membrane 10 on the polishing head attachment side. The upper surface of the reinforcing material 112 is exposed on the inner periphery of the portion 14 to be bonded.

[0031] 7 shows a mounting structure 100 for mounting an elastic membrane 10 to a polishing head 20 of a CMP device according to embodiment 3. The polishing head 20 is formed in a cylindrical shape having the same outer diameter as the elastic membrane 10.

[0032] In the mounting structure 100 for mounting an elastic membrane 10 to a polishing head 20 of a CMP apparatus in embodiment 3, a reinforcing material 112 exposed to the intended bonding portion 14 on the polishing head mounting side of the elastic membrane 10 is bonded to the tip of the polishing head 20 via an adhesive layer 30.

[0033] The other configurations and effects are the same as those of the first embodiment. [Industrial Applicability]

[0034] The present invention is useful in the technical field of an elastic membrane and its mounting structure that is attached to a polishing head of a CMP apparatus and used to hold a wafer. [Explanation of symbols]

[0035] 100 Mounting structure 10 Elastic membrane 11 Membrane body 111 Silicone rubber layer 111a Wafer holding surface 112 Reinforcement 112a Upper and lower through holes 12 Cylindrical part 13 Annular section 14 Part to be glued 141 First adhesion part 142 Second adhesion part 15 Outer peripheral ring rubber layer (rubber layer on polishing head mounting side) 16 Inner annular rubber layer (rubber layer on the polishing head mounting side) 20 Polishing Head 21 Annular groove 22 Bracket 23 Membrane attachment part 231 First membrane attachment part 232 Second membrane attachment part 30 Adhesive layer 301 1st adhesive layer 302 Second adhesive layer

Claims

1. An elastic membrane attached to a polishing head of a CMP apparatus and used to hold a wafer, a silicone rubber layer having a wafer support surface; a plate-shaped reinforcing member made of a non-silicone material laminated on the side of the silicone rubber layer opposite to the wafer support surface; Equipped with a bottomed hole is formed on the silicone rubber layer on the opposite side to the wafer support surface, and the reinforcing member is fitted into the bottomed hole of the silicone rubber layer; The elastic film has the reinforcing material exposed at a portion to be bonded to the polishing head on the polishing head mounting side.

2. 2. The elastic membrane according to claim 1, The elastic membrane further comprises a polishing head attachment side rubber layer disposed so as to sandwich the reinforcing material between the silicone rubber layer and the elastic membrane.

3. 3. The elastic membrane according to claim 2, The polishing head attachment side rubber layer is an elastic film formed of the same crosslinked silicone rubber as the silicone rubber layer.

4. 3. The elastic membrane according to claim 2, an elastic membrane in which the polishing head mounting side rubber layer is bonded to the silicone rubber layer through holes formed in the reinforcing material;

5. The elastic membrane according to claim 1, The elastic membrane, wherein the reinforcement material is adhered to the silicone rubber layer.

6. The elastic membrane according to claim 1, a cylindrical portion that is integrally provided so as to be continuous with the periphery of the silicone rubber layer and extend to a side opposite the wafer holding surface, an elastic membrane, the end of said tubular portion on the side of said silicone rubber layer being in contact with and engaged with the peripheral edge of said reinforcing material;

7. The elastic membrane according to claim 6, An elastic membrane further comprising an annular rubber layer that is continuous with the end of the tubular portion on the silicone rubber layer side, covers an outer peripheral portion of the reinforcing material, and is arranged to sandwich the reinforcing material between the silicone rubber layer and the annular rubber layer.

8. 8. A structure for mounting the elastic film according to claim 1 to a polishing head of a CMP apparatus, comprising: The reinforcing material exposed at the portion of the elastic membrane to be bonded is bonded to the polishing head via an adhesive layer.

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