Acid-labile hyperbranched copolymer and associated photoresist composition and method of forming an electronic device

Patent metadata

Field	Value
Publication number	US-9758610-B2
Application number	US-201514974329-A
Country	US
Kind code	B2
Filing date	Dec 18, 2015
Priority date	Dec 18, 2015
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

An acid-labile hyperbranched copolymer is formed by copolymerizing monomers that include a difunctional monomer and a mono(meth)acrylate ester. The difunctional monomer includes at least one formal group, acetal group, or ketal group that makes the copolymer acid-labile. The copolymer is useful as a component of a photoresist composition that provides low line width roughness, among other desirable photolithographic properties.

First claim

The invention claimed is:

1. An acid-labile hyperbranched copolymer, comprising the product of copolymerizing monomers comprising
an acid-labile difunctional monomer having the structure

wherein each occurrence of R 1 is independently hydrogen, fluoro, methyl, trifluoromethyl, or cyano; each occurrence of R 2 and R 3 is independently hydrogen, unsubstituted or substituted C 1-18 linear or branched alkyl, unsubstituted or substituted C 3-18 cycloalkyl, unsubstituted or substituted C 6-18 aryl, or unsubstituted or substituted C 3-18 heteroaryl, and R 2 and R 3 are not covalently linked, or covalently linked to each other to form a ring that includes —R 2 —C—R 3 —; each occurrence of L 1 , L 2 , and L 3 is independently unsubstituted or substituted C 1-8 -alkylene, unsubstituted or substituted —C(═O)—C 1-8 -alkylene, unsubstituted or substituted —C(═O)—(C 1-8 -alkylene)-C(═O)—, unsubstituted or substituted —(C 1-8 -alkylene)-O—(C 1-8 -alkylene)-, unsubstituted or substituted —C(═O)—(C 1-8 -alkylene)-O—(C 1-8 -alkylene)-, or unsubstituted or substituted —C(═O)—(C 1-8 -alkylene)-O—(C 1-8 -alkylene)-C(═O)—; each occurrence of X is independently 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, or —C(═O)—O—wherein the carbonyl carbon is bound to the adjacent carbon atom that is itself bound to R 1 ; and x is 1, 2, or 3; and
a mono(meth)acrylate ester comprising a base-solubility-enhancing mono(meth)acrylate ester, an acid-labile mono(meth)acrylate ester, a photoacid-generating mono(meth)acrylate ester, or a combination thereof

to form a copolymer having a weight average molecular weight of 10,000 to 1,000,000 grams/mole;
wherein the copolymerized monomers exclude styrene and substituted styrenes.

2. The copolymer of claim 1 , wherein each occurrence of L 1 , L 2 , and L 3 is independently C 2-4 -alkylene, and each occurrence of X is —C(═O)—O— wherein the carbonyl carbon is bound to the adjacent carbon atom that is itself bound to R 1 .

3. The copolymer of claim 1 , wherein each occurrence of R 2 and R 3 is independently hydrogen, methyl, or ethyl; or R 2 and R 3 are covalently linked to each other to form tetramethylene (—(CH 2 ) 4 —) or pentamethylene (—(CH 2 ) 5 —).

4. The copolymer of claim 1 , wherein x is 1.

5. The copolymer of claim 1 , wherein the acid-labile difunctional monomer has the structure

wherein R 1 , R 2 , R 3 , and L are defined as in claim 1 .

6. The copolymer of claim 1 , wherein the monomers comprise
5 to 30 mole percent of the acid-labile difunctional monomer,
20 to 88 mole percent of the base-solubility-enhancing mono(meth)acrylate monomer,
5 to 50 mole percent of acid-labile mono(meth)acrylate monomer, and
2 to 20 mole percent of the photoacid-generating mono(meth)acrylate monomer.

7. An acid-labile hyperbranched copolymer, comprising the product of copolymerizing monomers comprising
an acid-labile difunctional monomers selected from the group consisting of

and combinations thereof; and
a mono(meth)acrylate ester comprising a base-solubility-enhancing mono(meth)acrylate ester, an acid-labile mono(meth)acrylate ester, a photoacid-generating mono(meth)acrylate ester, or a combination thereof

to form a copolymer.

8. A photoresist composition comprising the copolymer of claim 1 .

9. A method of forming an electronic device, comprising:
(a) applying a layer of the photoresist composition of claim 8 on a substrate;
(b) pattern-wise exposing the photoresist composition to activating radiation; and
(c) developing the exposed photoresist composition layer to provide a resist relief image.

Assignees

• Dow Global Technologies Llc

Inventors

• Kramer John W

Classifications

• G03F7/0392

  the macromolecular compound being present in a chemically amplified positive photoresist composition · CPC title

• G03F7/0397

  the macromolecular compound having an alicyclic moiety in a side chain · CPC title

• C08F220/22

  Esters containing halogen · CPC title

• C08F293/005 Primary

  using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent · CPC title

• G03F7/20

  Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) · CPC title