Chemical mechanical polishing pad and preparation thereof

Patent metadata

Field	Value
Publication number	US-11679531-B2
Application number	US-202117500669-A
Country	US
Kind code	B2
Filing date	Oct 13, 2021
Priority date	Oct 13, 2021
Publication date	Jun 20, 2023
Grant date	Jun 20, 2023

Abstract

The present invention concerns a chemical mechanical polishing pad having a polishing layer. The polishing layer contains an extruded sheet. The extruded sheet is prepared by extruding a compounded photopolymerizable composition followed by exposure to UV light.

First claim

We claim:

1. A process for making an extruded sheet to be used as a polishing layer in a chemical mechanical polishing pad suitable for polishing at least one of a semiconductor substrate, an optical substrate and a magnetic substrate, the process comprising:
(a) compounding a photopolymerizable composition comprising a block copolymer, a UV curable acrylate, and a photoinitiator in an extruder, wherein the photopolymerizable composition does not contain any organic solvent;
(b) extruding the compounded mixture of step (a) onto a support through a sheet die;
(c) passing the product of step (b) through a plurality of calendar rolls;
(d) exposing the product of step (c) to a source of UV light;
wherein said block copolymer is present at an amount of greater than 50 wt %, based on the total weight of an extruded sheet, and wherein after the UV curing in step (d), the extruded sheet having a Shore D hardness in the range of 40 to 70.

2. The process of claim 1 , further comprising an embossing step between steps (c) and (d) to create a pattern on the product of step (c).

3. The process of claim 1 , wherein said block copolymer is a triblock copolymer.

4. The process of claim 3 , wherein said triblock copolymer is a styrenic block copolymer.

5. The process of claim 4 , wherein said styrenic block copolymer is one or more members selected from the group consisting of a styrene-butadiene-styrene (SBS) block copolymer, a styrene-isoprene-styrene (SIS) block copolymer, a styrene-ethylene-butene-styrene (SEBS) block copolymer, a styrene-ethylene-propylene-styrene (SEPS) block copolymer, and mixtures thereof.

6. The process of claim 1 , wherein said block copolymer is present at an amount of greater than 65%.

7. The process of claim 1 , wherein said acrylate is one or more members selected from the group consisting of 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, and mixtures thereof.

8. The process of claim 1 , wherein the extruded sheet has a Shore D hardness in the range of 45 to 55.

9. The process of claim 1 , wherein said photopolymerizable composition further comprises a plasticizer.

Assignees

• Rohm & Haas Elect Materials Cmp Holdings Inc
• Dupont Electronics Inc

Inventors

• Qian Bainian
• Blomquist Robert M
• El-Sayed Lyla M
• Mills Michael E
• Reddy Kancharla-Arun
• Taylor Bradley K
• Xia Shijing

Classifications

• B29K2105/0038

  Plasticisers · CPC title

• B29K2096/04

  Block polymers · CPC title

• B29K2105/0085

  Copolymers · CPC title

• B29C35/0805 Primary

  using electromagnetic radiation · CPC title

• B29K2009/06

  SB polymers, i.e. butadiene-styrene polymers · CPC title