Fluorine-free fused ring heteroaromatic photoacid generators and resist compositions containing the same
AssigneeInternational Business Machines Corporation
InventorsSen Liu, Pushkara R. Varanasi
Life of this patent
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Abstract
The present invention relates to a fluorine-free photoacid generator (PAG) and a photoresist composition containing the same. The PAG is characterized by the presence of an onium cationic component and a fluorine-free fused ring heteroaromatic sulfonate anionic component containing one or more electron withdrawing substituents. The onium cationic component of the PAG is preferably a sulfonium or an iodonium cation. The photoresist composition further contains an acid sensitive imaging polymer. The photoresist composition is especially useful for forming material patterns on a semiconductor substrate using 193 nm (ArF) lithography.
Claims26
A fluorine-free photoacid generator, said photoacid generator comprising an onium cationic component and an anionic component of formula (I):
- wherein:
- X is S;
- Y is C;
- each of G1-G5 is selected from the group consisting of H;
- linear, branched, tertiary or cyclic alkyl;
- linear, branched, tertiary or cyclic alkoxyl;
- unsubstituted and substituted aromatic groups;
- unsubstituted and substituted heteroaromatic group;
- and an electron withdrawing moiety, provided that when at least one of G1-G5 is an electron withdrawing moiety;
- and
- wherein said onium cationic component is selected from the group consisting of sulfonium cations and iodonium cations.
A photoresist composition comprising:
- (a) an acid sensitive imaging polymer;
- and
- (b) a fluorine-free photoacid generator comprising an onium cationic component and an anionic component of formula (I):
- wherein:
- X is S;
- Y is C;
- each of G1-G5 is selected from the group consisting of H;
- linear, branched, tertiary or cyclic alkyl;
- linear, branched, tertiary or cyclic alkoxyl;
- unsubstituted and substituted aromatic groups;
- unsubstituted and substituted heteroaromatic group;
- and an electron withdrawing moiety, provided that at least one of G1-G5 is an electron withdrawing moiety;
- and
- wherein said onium cationic component is selected from the group consisting of sulfonium cations and iodonium cations.
A method of forming a patterned material feature on a substrate, said method comprising:
- (a) providing a material layer on a substrate;
- (b) forming a photoresist layer over said material layer, said photoresist comprising:
- (i) an acid sensitive imaging polymer;
- and
- (ii) a fluorine-free photoacid generator comprising an onium cationic component and an anionic component of formula (I):
- wherein:
- X is S;
- Y is C;
- and
- each of G1-G5 is selected from the group consisting of hydrogen;
- linear, branched, tertiary or cyclic alkyl;
- linear, branched, tertiary or cyclic alkoxyl;
- unsubstituted and substituted aromatic groups;
- unsubstituted and substituted heteroaromatic groups;
- and an electron withdrawing moiety;
- and at least one of G1-G5 is an electron withdrawing moiety;
- (c) patternwise exposing said photoresist layer to radiation, thereby creating a pattern of radiation-exposed regions in said photoresist layer;
- (d) selectively removing portions of said photoresist layer to expose portions of said material layer;
- and
- (e) etching or ion implanting said exposed portions of said material layer, thereby forming said patterned material feature.
Dependencies are inferred from the claim text.