Base reactive photoacid generators and photoresists comprising same
This invention relates to new photoacid generator compounds and photoresist compositions that comprise such compounds. In particular, the invention relates to photoacid generator compounds that comprise base-cleavable groups.
1. A photoacid generator compound of formula (I)
R 5 M + R 6 R 7 r − O 3 S—R 1 p —X y —(R 2 Z w R 3 ) x (I)
wherein each R 1 is chosen from (C 1 -C 10 )alkyl, heteroatom-containing (C 1 -C 10 )alkyl, fluoro(C 1 -C 10 )alkyl, heteroatom-containing fluoro (C 1 -C 10 )alkyl, (C 6 -C 10 )aryl, and fluoro(C 6 -C 10 )aryl; each R 2 is a chemical bond or a (C 1 -C 30 )hydrocarbyl group; each R 3 is H or a (C 1 -C 30 )hydrocarbyl group; R 5 , R 6 and R 7 independently are chosen from an optionally substituted carbocylic aryl group, an allyl group, and an optionally substituted (C 1 -C 20 )alkyl group; X is a chemical bond or a divalent linking group; Z is chosen from an acetoacetoxy ester, —C(O)—O—C(O)—R 1 —, —C(CF 3 ) 2 —, —COO—R f —, —SO 3 —R f —, —OCH 3-z (CH 2 OC(═O)—R f —) z , and a (C 5 -C 30 )cyclohydrocarbyl group comprising a base-reactive group chosen from fluoroalkyl esters, fluorosulfonate esters, and —C(CF 3 ) 2 O—; each R f is independently a fluoro(C 1 -C 10 )alkyl; p=0-6; w=1-3; x=1-4; y=0-5; z=1-2; r=0-1; M is S or I; wherein when M=I, r=0, and when M=S, r=1.
2. The photoacid generator compound of claim 1 wherein X is chosen from —C(O)O—, —C(O)S—, —SO 3 —, —S(O)—, —SO 2 —,
and combination thereof.
3. A photoresist composition comprising a photoacid generator compound of claim 1 .
4. A method for forming a photoresist relief image on a substrate comprising: (a) applying a coating layer of a photoresist composition of claim 3 on a substrate; and (b) exposing the photoresist coating layer to patterned activating radiation and developing the exposed photoresist layer to provide a relief image.
5. The method of claim 4 further comprising developing the exposed photoresist layer with aqueous alkaline developer whereby the one or more base-reactive groups undergo a bond-breaking reaction to provide one or more polar groups.
6. The photoacid generator compound of claim 1 wherein R 1 is (CR a 2 ) n , wherein each R a is chosen from H, F, (C 1 -C 10 )alkyl and fluoro(C 1 -C 10 )alkyl; and n=0-6.
7. The photoacid generator compound of claim 1 wherein R 3 is chosen from H, (C 1 -C 30 )alkyl, fluoro(C 1 -C 30 )alkyl and (C 6 -C 20 )aryl.
8. The photoacid generator compound of claim 1 wherein X is a divalent linking group of the formula —X 2 t1 —(Y 2 ═X 3 )X 3 t2 —, wherein X 2 ═O, S, or NR; Y 2 ═C, S, or S═O, X 3 ═O or S; t1=0 or 1; and t2=0 or 1.
9. The photoacid generator compound of claim 1 wherein the photoacid generator of formula (I) has a structure
10. The photoacid generator compound of claim 1 wherein Z is —C(CF 3 ) 2 O— or a (C 5 -C 30 )cyclohydrocarbyl group comprising —C(CF 3 ) 2 O—; and R 3 is H.