Photoresist composition and associated method of forming an electronic device

1. A photoresist composition comprising:

a first polymer comprising 60 to 100 mole percent of photoacid-generating repeat units, wherein each of the photoacid-generating repeat units comprises (a) photoacid-generating functionality and (b) base-solubility-enhancing functionality selected from the group consisting of tertiary carboxylic acid esters, secondary carboxylic acid esters wherein the secondary carbon is substituted with at least one unsubstituted or substituted C 6-40 aryl, acetals, ketals, lactones, sultones, alpha-fluorinated esters, beta-fluorinated esters, alpha,beta-fluorinated esters, polyalkyleneglycols, alpha-fluorinated alcohols, and combinations thereof; and

a second polymer that exhibits a change in solubility in an alkali developer under the action of acid

wherein the photoacid-generating repeat units of the first polymer have the structure

wherein

R 1 is independently in each of the repeat units H, F, —CN, C 1-10 alkyl, or C 1-10 fluoroalkyl;

L 1 is independently in each of the repeat units —O—, —C(O)—O—, unsubstituted C 6-18 arylene, or substituted C 6-18 arylene;

m is 1;

L 2 is independently in each of the repeat units an unsubstituted or substituted C 1-20 hydrocarbylene, wherein the substituted C 1-20 hydrocarbylene can, optionally, include one or more in-chain divalent heteroatom-containing groups that is —O—, —S—, —NR 2 , —PR 2 —, —C(O)—, —OC(O)O—, —N(R 2 )C(O)—, —C(O)N(R 2 )—, —OC(O)N(R 2 )—, —N(R 2 )C(O)O—, —S(O)—, —S(O) 2 —, —N(R 2 )S(O) 2 —, —S(O) 2 N(R 2 )—, —OS(O) 2 —, or —S(O) 2 O—, wherein R 2 is H or C 1-12 hydrocarbyl;

Z − is independently in each of the repeat units sulfonate (—SO 3 − ), sulfonamidate (anion of sulfonamide; —S(O) 2 N − R 3 , wherein R 3 is H or unsubstituted or substituted C 1-12 hydrocarbyl), or sulfonimidate (anion of sulfonimide; —S(O) 2 N − S(O) 2 R 3 , wherein R 3 is H or unsubstituted or substituted C 1-12 hydrocarbyl);

Q + is photoacid-generating cation; and

at least one of L 1 , L 2 (when m is 1), and Q + comprises the base-solubility-enhancing functionality.

2. The photoresist composition of claim 1 , wherein the first polymer comprises 95 to 100 mole percent of the photoacid-generating repeat units, and wherein the photoacid-generating repeat units are derived from a single monomer.

3. The photoresist composition of claim 1 , wherein the first polymer comprises 95 to 100 mole percent of the photoacid-generating repeat units, and wherein the photoacid-generating repeat units are derived from at least two different monomers.

4. The photoresist composition of claim 1 , wherein

R 1 is independently in each of the photoacid-generating repeat units H or methyl;

L 1 is —C(O)—O— in each of the photoacid-generating repeat units;

m is 1 in each of the photoacid-generating repeat units;

L 2 is independently in each of the photoacid-generating repeat units a fluorine-substituted C 2-20 hydrocarbylene, wherein the fluorine-substituted C 2-20 hydrocarbylene can, optionally, include one or more in-chain divalent heteroatom-containing groups that is —O—, —OC(O)—, or —C(O)O—;

Z − is sulfonate (—SO 3 − ) in each of the photoacid-generating repeat units; and

Q + is independently in each of the photoacid-generating repeat units an unsubstituted or substituted tri(C 1-40 -hydrocarbyl)sulfonium ion, or an unsubstituted or substituted di(C 1-40 -hydrocarbyl)iodonium ion.

5. The photoresist composition of claim 4 ,

wherein the second polymer comprises 10 to 65 mole percent of acid-labile repeat units, 0 to 50 weight percent of base-labile repeat units, 0 to 40 mole percent of base-soluble repeat units, and 0 to 15 mole percent of photoacid-generating repeat units;

wherein the photoresist composition comprises, on a dry weight basis,

20 to 80 weight percent of the first polymer,

10 to 60 weight percent of the second polymer, and

0.5 to 10 weight percent of a quencher.

6. A method of forming an electronic device, comprising:

(a) applying a layer of the photoresist composition of claim 1 on a substrate;

(b) pattern-wise exposing the photoresist composition layer to activating radiation; and

(c) developing the exposed photoresist composition layer to provide a resist relief image.