Photoacid-generating compound and associated polymer, photoresist composition, and method of forming a photoresist relief image
A photoacid-generating compound has the structure wherein m, n, R 1 , R 2 , X, Y, and Z − are defined herein. The photoacid-generating compound exhibits strong absorption and chemical sensitivity to extreme ultraviolet radiation, while also absorbing longer wavelengths with desirably reduced chemical sensitivity. Also described are a polymer incorporating the residue of a polymerizable version of the photoacid-generating compound, a photoresist composition that includes the photoacid-generating compound, the polymer, or a combination thereof, and a method of forming a photoresist relief image using the photoresist composition.
1. A photoacid-generating compound having the structure
wherein
m is 0, 1, 2, 3, 4, 5, or 6;
n is 0, 1, 2, 3, 4, or 5;
R 1 and R 2 are each independently hydrogen, halogen, hydroxyl, carboxyl (—CO 2 H), unsubstituted or substituted C 1-12 alkyl, unsubstituted or substituted C 1-12 alkoxyl, unsubstituted or substituted C 2-12 alkanoyl, unsubstituted or substituted C 2-12 alkanoyloxy, unsubstituted or substituted C 2-12 alkoxycarbonyl, unsubstituted or substituted C 3-12 anhydride, unsubstituted or substituted C 4-12 lactone, unsubstituted or substituted C 4-18 acetal, unsubstituted or substituted C 5-18 ketal, unsubstituted or substituted C 6-12 aryl provided that R 1 and R 2 are not linked to form a cycloaryl group;
X and Y are independently at each occurrence halogen, hydroxyl, amino, thiol, carboxyl, amide, cyano, nitro, unsubstituted or substituted C 1-18 alkyl, unsubstituted or substituted C 1-18 alkoxyl, unsubstituted or substituted C 6-18 aryl, unsubstituted or substituted C 6-18 aryloxyl, unsubstituted or substituted C 7-18 alkylaryl, unsubstituted or substituted C 7-18 alkylaryloxyl, unsubstituted or substituted C 2-12 alkoxycarbonyl, unsubstituted or substituted C 4-18 acetal, or unsubstituted or substituted C 5-18 ketal; and
Z − is an anion comprising a sulfonate group, a sulfonamidate group, a sulfonimidate group, a methide group, or a borate group; wherein Z − optionally comprises a polymerizable group selected from vinyl, and an acryloyl group of the form —C(O)C(R 11 )═CH 2 , wherein R 11 is hydrogen, fluoro, cyano, C 1-9 alkyl, or C 1-9 fluoroalkyl;
provided that the photoacid-generating compound comprises at most one polymerizable group.
2. The photoacid-generating compound of claim 1 , wherein R 1 and R 2 are each independently hydrogen, C 1-12 alkyl, or C 2-12 alkoxycarbonyl.
3. The photoacid-generating compound of claim 1 , wherein n is 1, 2, or 3; and X is independently at each occurrence C 1-18 alkyl or C 2-12 alkoxycarbonyl.
4. The photoacid-generating compound of claim 1 , wherein m is zero.
5. The photoacid-generating compound of claim 1 , having the structure
wherein
q is 0, 1, or 2;
R 1a and R 2a are each independently C 1-12 alkyl;
R 5 , R 6 , and R 7 are each independently an unsubstituted or substituted C 1-14 hydrocarbyl, wherein two of R 5 , R 6 , and R 7 can be connected to form a cyclic structure; and wherein the total number of carbon atoms in R 5 , R 6 , and R 7 does not exceed 16;
X 1 is independently at each occurrence C 1-12 alkyl, or C 2-12 alkoxy carbonyl; and
Z − is an anion comprising a sulfonate group, a sulfonamidate group, a sulfonimidate group, a methide group, or a borate group.
6. The photoacid-generating compound of claim 1 , having the structure
wherein
q is 0, 1, 2, or 3;
X 1 is independently at each occurrence an unsubstituted or substituted C 1-18 alkyl; and
Z − is an anion comprising a sulfonate group, a sulfonamidate group, a sulfonimidate group, a methide group, or a borate group.
7. The photoacid-generating compound of claim 1 , wherein one of R 1 or R 2 or Z − , or one occurrence of X, or one occurrence of Y, is a polymerizable group, provided that if one occurrence of X is the polymerizable group, then n is 1, 2, or 3, and provided that if one occurrence of Y is the polymerizable group, then m is 1, 2, or 3.
8. A polymer comprising repeat units derived from the photoacid-generating compound of claim 7 .
9. A photoresist composition comprising the photoacid-generating compound of any one of claims 1 to 6 .
10. A method of forming a photoresist relief image, comprising:
(a) applying a layer of the photoresist composition of claim 9 on a substrate to form a photoresist layer;
(b) pattern-wise exposing the photoresist layer to activating radiation to form an exposed photoresist layer; and
(c) developing the exposed photoresist layer to provide a photoresist relief image.
11. A photoresist composition comprising the polymer of claim 8 .