Method for securing a polishing pad to a platen for use in chemical-mechanical polishing of wafers
View Patent ↗The present invention is related to a method for securing a polishing pad to the platen for use in chemical-mechanical polishing. Specifically, a polishing pad is attached to a platen using a reclosable, hook-and-pile fastener, whereby the platen-attachment fastener may be reused. Separate embodiments are disclosed for attaching porous and nonporous polishing pads.
1. In a CMP apparatus comprising a polishing pad having a working-surface section and a nonworking-surface section, a platen for holding said polishing pad, and means for securing said polishing pad to said platen, the improvement comprising:
said means for securing said polishing pad to said platen comprising hook-and-pile fastening means;
said hook-and-pile fastening means comprising a first portion attached to said polishing pad, and a second portion attached to said platen for mating with said first portion;
said hook-and-pile fastening means having a shear strength in the range of 50-250 kPa, and peel strength in the range of 0.2-0.6 N/m.
2. The CMP apparatus according to claim 1 , wherein said polishing pad comprises a nonporous polishing pad;
said means for securing comprising first adhesive means on said nonworking-surface section of said polishing pad for attaching said first portion to said polishing pad, and second adhesive means on said platen for attaching said second portion to said platen.
3. The CMP apparatus according to claim 1 , wherein said polishing pad comprises a porous polishing pad;
said polishing pad comprising a thermoplastic boundary layer on said nonworking-surface section of said polishing pad;
said means for securing comprising first adhesive means attached to said thermoplastic boundary layer on said nonworking-surface section of said polishing pad for attaching said first portion to said polishing pad, and second adhesive means on said platen for attaching said second portion to said platen.
4. The CMP apparatus according to claim 1 , wherein said hook-and-pile fastening means is made of CMP-non-degradable material.
5. The CMP apparatus according to claim 1 , wherein said polishing pad comprises a porous polishing pad;
said nonworking-surface section of said polishing pad comprising a bonding layer fused thereto; said means for securing comprising first adhesive means attached to said bonding layer for attaching said first portion to said polishing pad, and second adhesive means on said platen for attaching said second portion to said platen.
6. The CMP apparatus according to claim 5 , wherein said bonding layer is made of a water-impervious material in order to prevent CMP slurry from contacting said first and second adhesive means, having a thickness of between 0.025-0.050 mm.
7. The CMP apparatus according to claim 1 , wherein said first portion of said hook-and-pile fastening means comprises the hook-portion thereof having hooks, and said second portion of said hook-and-pile fastening means comprises the pile-portion thereof having loops; said hooks of said hook-portion of said hook-and-pile fastening means being relatively stiff, and said loops of said pile-portion of said hook-and-pile fastening means being relatively soft.
8. A method of securing a polishing pad to a platen of a CMP apparatus, the polishing pad having a working-surface section and a nonworking-surface section, the polishing pad comprising a first portion of a hook-and-pile fastening means attached to the nonworking-surface section, and the platen comprising a pad-supporting surface having a second, mating portion of the hook-and-pile fastening means, said method comprising:
(a) removably attaching the nonworking-surface section of the polishing pad to the pad-supporting surface of the platen with hook-and-pile fastening means having a shear strength in the range of 50-250 kPa, and peel strength in the range of 0.2-0.6 N/m.;
(b) said step of removably attaching comprising attaching the first portion of the hook-and-pile fastening means to the second portion of the hook-and-pile fastening means.
9. The method of securing a polishing pad to a platen of a CMP apparatus according to claim 8 , further comprising:
(c) after said step of removably attaching, removing the polishing pad from the platen when the polishing pad has become worn;
(d) said step of removing the polishing pad comprising peeling the first portion of the hook-and-pile fastening means from the second portion of the hook-and-pile fastening means.
10. The method of securing a polishing pad to a platen of a CMP apparatus according to claim 9 , further comprising:
(e) removably attaching the nonworking-surface section of another, new said polishing pad to the pad-supporting surface of the platen;
(f) said step of removably attaching the nonworking-surface section of another, new said polishing pad comprising attaching the first portion of the hook-and-pile fastening means of the nonworking-surface section thereof to said second portion of the hook-and-pile fastening means used in said step of attaching the first portion of the hook-and-pile fastening means to the second portion of the hook-and-pile fastening means.