Soft and conditionable chemical mechanical window polishing pad

Patent metadata

Field	Value
Publication number	US-9238295-B2
Application number	US-201313906765-A
Country	US
Kind code	B2
Filing date	May 31, 2013
Priority date	May 31, 2013
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

A chemical mechanical polishing pad is provided containing: a polishing layer; a plug in place endpoint detection window block; a rigid layer; and, a hot melt adhesive bonding the polishing layer to the rigid layer; wherein the polishing layer comprises the reaction product of ingredients, including: a polyfunctional isocyanate; and, a curative package; wherein the curative package contains an amine initiated polyol curative and a high molecular weight polyol curative; wherein the polishing layer exhibits a density of greater than 0.6 g/cm 3 ; a Shore D hardness of 5 to 40; an elongation to break of 100 to 450%; and, a cut rate of 25 to 150 μm/hr; and, wherein the polishing layer has a polishing surface adapted for polishing the substrate. Also provide are methods of making and using the chemical mechanical polishing pad.

First claim

We claim:

1. A chemical mechanical polishing pad, comprising:
a polishing layer having a polishing surface and a base surface, a counterbore opening, a through opening, an average thickness, T P-avg , measured in a direction perpendicular to the polishing surface from the polishing surface to the base surface;
a plug in place endpoint detection window block having an average thickness, T W-avg , along an axis perpendicular to a plane of the polishing surface;
a rigid layer having a top surface and a bottom surface;
a hot melt adhesive interposed between the base surface of the polishing layer and the top surface of the rigid layer; wherein the hot melt adhesive bonds the polishing layer to the rigid layer;
optionally, a pressure sensitive platen adhesive; wherein the pressure sensitive platen adhesive is disposed on the bottom surface of the rigid layer;
optionally, a release liner; wherein the pressure sensitive platen adhesive is interposed between the bottom surface of the rigid layer and the optional release liner;
wherein the polishing layer comprises the reaction product of ingredients, comprising:
a polyfunctional isocyanate; and
a curative package, comprising:
at least 5 wt % of an amine initiated polyol curative, wherein the amine initiated polyol curative contains at least one nitrogen atom per molecule; wherein the amine initiated polyol curative has an average of at least three hydroxyl groups per molecule;
25 to 95 wt % of a high molecular weight polyol curative, wherein the high molecular weight polyol curative has a number average molecular weight, M N , of 2,500 to 100,000; and wherein the high molecular weight polyol curative has an average of 5 to 7 hydroxyl groups per molecule; and
0 to 70 wt % of a difunctional curative;

wherein the polishing layer exhibits a density of greater than 0.6 g/cm 3 ; a Shore D hardness of 5 to 40; an elongation at break of 100 to 450%; and
a cut rate of 25 to 150 μm/hr;

wherein the through opening extends through the polishing layer from the polishing surface to the base surface;
wherein the counterbore opening opens on the polishing surface, enlarges the through opening and forms a ledge;
wherein the counterbore opening has an average depth, D O-avg , from a plane of the polishing surface to the ledge measured in a direction perpendicular to the plane of the polishing surface;
wherein the average depth, D O-avg , is less than the average thickness, T P-avg ;
wherein the plug in place endpoint detection window block is disposed within the counterbore opening; and
wherein the plug in place endpoint detection window block is bonded to the polishing layer.

2. The chemical mechanical polishing pad of claim 1 , wherein the top surface of the rigid layer is ungrooved; and wherein the bottom surface of the rigid layer is ungrooved.

3. The chemical mechanical polishing pad of claim 1 , wherein the top surface and the bottom surface of the rigid layer each have a roughness, Ra, of 1 to 500 nm.

4. The chemical mechanical polishing pad of claim 1 , wherein the rigid layer is made of a biaxially oriented polyethylene terephthalate; wherein the rigid layer has an average thickness of 6 to 10 mils; and wherein the rigid layer exhibits a Young's Modulus of 3,000 to 7,000 MPa.

5. The chemical mechanical polishing pad of claim 1 ,
wherein the polyfunctional isocyanate is an isocyanate-terminated urethane prepolymer having 2 to 12 wt % unreacted NCO groups; and
wherein the curative package, consists of:
5 to 20 wt % of the amine initiated polyol curative, wherein the amine initiated polyol curative contains two nitrogen atoms per molecule; wherein the amine initiated polyol curative has an average of 4 hydroxyl groups per molecule; and

wherein the amine initiated polyol curative has a number average molecular weight, M N , of 200 to 400;
50 to 75 wt % of the high molecular weight polyol curative, wherein the high molecular weight polyol curative has a number average molecular weight, M N , of 10,000 to 12,000; and wherein the high molecular weight polyol curative has an average of 6 hydroxyl groups per molecule;
10 to 30 wt % of the difunctional curative; wherein the difunctional curative is a diamine curative selected from the group consisting of

4,4′-methylene-bis-(2-chloroaniline) (MBOCA);
4,4′-methylene-bis-(3-chloro-2,6-diethylaniline) (MCDEA); and isomers thereof;
wherein the stoichiometric ratio of the reactive hydrogen groups in the curative package to the unreacted isocyanate groups in the polyfunctional isocyanate is 0.95 to 1.05;
wherein the polishing layer exhibits a density of 0.75 to 1.0 g/cm 3 ; a Shore D hardness of 5 to 20; an elongation at break of 150 to 300%; and a cut rate of 30 to 60 μm/hr.

6. The chemical mechanical polishing pad of claim 5 , wherein the isocyanate-terminated urethane prepolymer has 5 to 7 wt % unreacted NCO groups; and wherein the isocyanate-terminated urethane prepolymer exhibits a number average molecular weight, M N , of 400 to 2,500.

7. The chemical mechanical polishing pad of claim 1 , wherein the chemical mechanical polishing pad consists of: the polishing layer, the plug in place endpoint detection window block, the rigid layer, the hot melt adhesive interposed between the polishing layer and the rigid layer, the pressure sensitive platen adhesive disposed on the bottom surface of the rigid layer and the release liner;
wherein the polyfunctional isocyanate is an isocyanate-terminated urethane prepolymer having 2 to 12 wt % unreacted NCO groups; and
wherein the curative package, consists of:
5 to 20 wt % of the amine initiated polyol curative, wherein the amine initiated polyol curative contains two nitrogen atoms per molecule; wherein the amine initiated polyol curative has an average of 4 hydroxyl groups per molecule; and

wherein the amine initiated polyol curative has a number average molecular weight, M N , of 200 to 400;
50 to 75 wt % of the high molecular weight polyol curative, wherein the high molecular weight polyol curative has a number average molecular weight, M N , of 10,000 to 12,000; and wherein the high molecular weight polyol curative has an average of 6 hydroxyl groups per molecule;
10 to 30 wt % of the difunctional curative; wherein the difunctional curative is a diamine curative selected from the group consisting of

4,4′-methylene-bis-(2-chloroaniline) (MBOCA);
4,4′-methylene-bis-(3-chloro-2,6-diethylaniline) (MCDEA); and isomers thereof;
wherein the stoichiometric ratio of the reactive hydrogen groups in the curative package to the unreacted isocyanate groups in the polyfunctional isocyanate is 0.95 to 1.05;
wherein the polishing layer exhibits a density of 0.75 to 1.0 g/cm 3 ; a Shore D hardness of 5 to 20; an elongation at break of 150 to 300%; and a cut rate of 30 to 60 μm/hr.

8. The chemical mechanical polishing pad of claim 7 , wherein the isocyanate-terminated urethane prepolymer has 5 to 7 wt % unreacted NCO groups; and, wherein the isocyanate-terminated urethane prepolymer exhibits a number average molecular weight, M N , of 400 to 2,500.

9. The chemical mechanical polishing pad of claim 1 , wherein the polishing layer is adapted for polishing a substrate selected from at least one of a magnetic substrate, an optical substrate and a semiconductor substrate.

10. The chemical mechanical polishing pad of claim 1 , wherein the polishing layer is adapted for polishing a semiconductor wafer.

11. The chemical mechanical polishing pad of claim 1 , wherein the polyfunctional isocyanate is an isocyanate-terminated urethane prepolymer having 2 to 12 wt % unreacted NCO groups.

12. The chemical mechanical polishing pad of claim

Assignees

• Rohm & Haas Elect Mat
• Dow Global Technologies Llc

Inventors

• Qian Bainian
• Jensen Michelle K
• Degroot Marty W
• Repper Angus
• Murnane James
• Hendron Jeffrey James
• Nowland John G
• James David B
• Yeh Fengji

Classifications

• B24B37/24

  characterised by the composition or properties of the pad materials · CPC title

• B24B37/22

  characterised by a multi-layered structure · CPC title

• B24B37/245 Primary

  Pads with fixed abrasives · CPC title

• B24D11/001

  Manufacture of flexible abrasive materials · CPC title

• B24B37/205 Primary

  provided with a window for inspecting the surface of the work being lapped · CPC title