US 5,691,111 AGranted

Photosensitive resin composition useful as resist for deep UV lithography containing sulfonium salts

AssigneeNEC Corporation

InventorsShigeyuki Iwasa, Kaichiro Nakano, Etsuo Hasegawa

Life of this patent

Estimating the term…

Loading patent…

Abstract

The invention provides a photosensitive resin composition useful as a photoresist of chemical amplification type for deep UV lithography such as ArF excimer laser lithography. The resin composition contains, as an acid generator, an alkylsulfonium salt of the general formula (I), wherein R.sup.1 is a C.sub.7 to C.sub.12 alkyl having a bridged alicyclic structure or a C.sub.5 to C.sub.7 monocyclic alkyl, R.sup.2 is an alkyl, R.sup.3 is a C.sub.5 to C.sub.7 .beta.-oxomonocyclic alkyl or a C.sub.7 to C.sub.10 bridged cyclic alkyl having oxo group at the .beta.-position. The general formula (I) is inclusive of novel alkylsulfonium salts in which R.sup.1 is norbornyl group, adamantyl group or cyclohexyl group, R.sup.2 is methyl group and R.sup.3 is .beta.-oxocyclohexyl group or .beta.-oxonorbornane-2-yl group. ##STR1##

Claims22

Dependent claims

A photosensitive resin composition which is useful as a photoresist for photolithographic processes using deep UV radiation, the resin composition comprising an organic polymer having at least one acidolysis-susceptible functional group and an alkylsulfonium salt represented by the general formula (1A) or the general formula (1B):

##STR14## where R.sup.1 is a C.sub.7 to C.sub.12 alkyl group having a C.sub.7 to C.sub.10 bridged alicyclic hydrocarbon structure, R.sup.2 is (i) a C.sub.7 to C.sub.12 alkyl group having a C.sub.7 to C.sub.10 bridged alicyclic hydrocarbon structure or (ii) a C.sub.1 to C.sub.7 linear, branched or monocyclic alkyl group, R.sup.3 is a C.sub.5 to C.sub.7 .beta.-oxomonocyclic alkyl group, and Y.sup.- is a counter ion:
##STR15## where R.sup.1' is a C.sub.5 to C.sub.7 monocyclic alkyl group, R.sup.2' is (i) a C.sub.5 to C.sub.7 monocyclic alkyl group or (ii) a C.sub.1 to C.sub.8 linear, branched or monocyclic alkyl group, R.sup.3' is a C.sub.7 to C.sub.10 bridged cyclic alkyl group having oxo group at the .beta.-position, and Y.sup.- is a counter ion.

Dependencies are inferred from the claim text.