Controlled-expansion CMP PAD casting method

Patent metadata

Field	Value
Publication number	US-9586304-B2
Application number	US-201414576927-A
Country	US
Kind code	B2
Filing date	Dec 19, 2014
Priority date	Dec 19, 2014
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

The invention provides a method of manufacturing a polishing pad suitable for planarizing at least one of semiconductor, optical and magnetic substrates. The method obtains a liquid polyurethane material formed from an isocyanate-terminated molecule and a curative agent. The liquid polyurethane material has a T gel temperature and contains fluid-filled polymeric microspheres. The fluid-filled polymeric microspheres are a blend of preexpanded and unexpanded fluid-filled polymeric microspheres. The preexpanded and unexpanded fluid-filled polymeric microspheres each have a T start temperature where diameter of the preexpanded and unexpanded fluid-filled polymeric microspheres increases and a T max temperature where gas escapes to decrease diameter of the expanded and unexpanded fluid-filled polymeric microspheres. The cured polyurethane matrix contains preexpanded and expanded fluid-filled polymeric microspheres.

First claim

The invention claimed is:

1. A method of manufacturing a polishing pad suitable for planarizing at least one of semiconductor, optical and magnetic substrates, the method comprising the following:
obtaining a liquid polyurethane material formed from an isocyanate-terminated molecule and a curative agent, the liquid polyurethane material having a T gel temperature and containing fluid-filled polymeric microspheres, the fluid-filled polymeric microspheres are a blend of preexpanded and unexpanded fluid-filled polymeric microspheres, the preexpanded and unexpanded fluid-filled polymeric microspheres each having a T start temperature where diameter of the preexpanded and unexpanded fluid-filled polymeric microspheres increases at temperatures equal to or above the T start temperature, and a T max temperature where gas escapes through the preexpanded and unexpanded fluid-filled polymeric microspheres to decrease diameter of the expanded and unexpanded fluid-filled polymeric microspheres, with the T start temperature of the unexpanded fluid-filled polymeric microspheres being at least 5° C. less than the T gel temperature of the liquid polyurethane material;
casting the liquid polyurethane material containing the blend of preexpanded and unexpanded fluid-filled polymeric microspheres to react the isocyanate-terminated molecule and the curative agent;
heating the blend of preexpanded and unexpanded fluid-filled polymeric microspheres in the liquid polyurethane material to a temperature of at least T start of the unexpanded fluid-filled polymeric microspheres to increase the diameter of the unexpanded fluid-filled polymeric microspheres, the heating being to a temperature less than the T max temperature where gas escapes through the preexpanded and unexpanded fluid-filled polymeric microspheres, the heating being to form a blend of preexpanded and expanded fluid-filled polymeric microspheres in the liquid polyurethane material;
curing the blend of preexpanded and expanded fluid-filled polymeric microspheres in the liquid polyurethane material to solidify the liquid polyurethane material into a polyurethane matrix containing the preexpanded and expanded fluid-filled polymeric microspheres; and
finishing the polishing pad from the cured polyurethane matrix containing the preexpanded and expanded fluid-filled polymeric microspheres wherein final diameter of the preexpanded and expanded fluid-filled polymeric microspheres is less than that achieved from the T max temperature in air and a majority of fluid contained in the preexpanded and unexpanded fluid-filled polymeric microspheres remains in the preexpanded and expanded fluid-filled polymeric microspheres.

2. The method of claim 1 including the additional step of mixing the blend of preexpanded and unexpanded fluid-filled polymeric microspheres in the liquid polyurethane material before casting.

3. The method of claim 1 wherein the T start temperature of the unexpanded fluid-filled polymeric microspheres is at least 10° C. less than the T gel temperature of the liquid polyurethane material.

4. The method of claim 1 wherein the casting is into a cake mold to form a polyurethane cake structure; and including the additional steps of removing the polyurethane cake structure from the mold and skiving the cake structure into multiple polyurethane sheets; and the forming the polishing pads is from the polyurethane sheets.

5. The method of claim 1 wherein the casting includes pouring the liquid polyurethane material and the blend of preexpanded and expanded fluid-filled polymeric microspheres around a transparent block and the forming the polishing pad includes a transparent window in the polishing pad.

6. A method of manufacturing a polishing pad suitable for planarizing at least one of semiconductor, optical and magnetic substrates, the method comprising the following:
obtaining a liquid polyurethane material formed from an isocyanate-terminated molecule and a curative agent, the liquid polyurethane material having a T gel temperature and containing fluid-filled polymeric microspheres, the fluid-filled polymeric microspheres are a blend of preexpanded and unexpanded fluid-filled polymeric microspheres filled with isobutane, isopentane or a mixture of isobutane and isopentane, the preexpanded and unexpanded fluid-filled polymeric microspheres each having a T start temperature where diameter of the preexpanded and unexpanded fluid-filled polymeric microspheres increases at temperatures equal to or above the T start temperature, and a T max temperature where gas escapes through the preexpanded and unexpanded fluid-filled polymeric microspheres to decrease diameter of the expanded and unexpanded fluid-filled polymeric microspheres, with the T start temperature of the unexpanded fluid-filled polymeric microspheres being at least 5° C. less than the T gel temperature of the liquid polyurethane material;
casting the liquid polyurethane material containing the blend of preexpanded and unexpanded fluid-filled polymeric microspheres to react the isocyanate-terminated molecule and the curative agent;
heating the blend of preexpanded and unexpanded fluid-filled polymeric microspheres in the liquid polyurethane material to a temperature of at least T start of the unexpanded fluid-filled polymeric microspheres to increase the diameter of the unexpanded fluid-filled polymeric microspheres, the heating being to a temperature less than the T max temperature where gas escapes through the preexpanded and unexpanded fluid-filled polymeric microspheres, the heating being to form a blend of preexpanded and expanded fluid-filled polymeric microspheres in the liquid polyurethane material;
curing the blend of preexpanded and expanded fluid-filled polymeric microspheres in the liquid polyurethane material to solidify the liquid polyurethane material into a polyurethane matrix containing the preexpanded and expanded fluid-filled polymeric microspheres; and
finishing the polishing pad from the cured polyurethane matrix containing the preexpanded and expanded fluid-filled polymeric microspheres wherein final diameter of the preexpanded and expanded fluid-filled polymeric microspheres is less than that achieved from the T max temperature in air and a majority of fluid contained in the preexpanded and unexpanded fluid-filled polymeric microspheres remains in the preexpanded and expanded fluid-filled polymeric microspheres.

7. The method of claim 6 including the additional step of mixing the blend of preexpanded and unexpanded fluid-filled polymeric microspheres in the liquid polyurethane material before casting.

8. The method of claim 6 wherein with the T start temperature of the unexpanded fluid-filled polymeric microspheres is at least 10° C. less than the T gel temperature of the liquid polyurethane material.

9. The method of claim 6 wherein the casting is into a cake mold to form a polyurethane cake structure; and including the additional steps of removing the polyurethane cake structure from the mold and skiving the cake structure into multiple polyurethane sheets; and the forming the polishing pads is from the polyurethane sheets.

10. The method of claim 6 wherein the casting includes pouring the liquid polyurethane material and the blend of preexpanded and expanded fluid-filled polymeric microspheres around a transparent block and the forming the polishing pad includes a transparent window in the polishing pad.

Assignees

• Rohm & Haas Elect Materials Cmp Holdings Inc

Inventors

• Qian Bainian
• Wank Andrew
• Jacob George C

Classifications

• H10P95/062

  involving a dielectric removal step · CPC title

• C08L75/04

  Polyurethanes · CPC title

• C08J2375/04

  Polyurethanes · CPC title

• C08G73/1007

  from tetracarboxylic acids or derivatives and diamines · CPC title

• C08G18/4854

  Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group · CPC title