The present invention relates to a novel polymer comprising at least one unit derived from an ethylenically unsaturated compound containing at least one cyano functionality and at least one nonaromatic cyclic unit. The novel polymer is particularly useful when used in a photoresist composition sensitive in the deep ultraviolet region.
The present invention provides polymers that are useful in negative resist compositions. Polymers of the present invention comprise (1) a first monomer having a polar functional group; (2) a second monomer; and optionally, (3) a third monomer that imparts at least one characteristic selected from crosslinkable functionality, etch resistance, and solubility modulation. The first monomer provides an acid catalyzed polarity switch upon elimination of the polar functional group, whereas, the second monomer provides aqueous dissolution. The polymers of the present invention may be incorporated into negative resist compositions, which may also include photoacid generators, crosslinking agents, basic compounds, solvents, dissolution accelerators, photobase generators, latent basic compounds, surfactants, adhesion promoters, and anti-foaming agents.
The present invention provides polymers that are useful in negative resist compositions. Polymers of the present invention comprise (1) a first monomer having a polar functional group; (2) a second monomer; and optionally, (3) a third monomer that imparts at least one characteristic selected from crosslinkable functionality, etch resistance, and solubility modulation. The first monomer provides an acid catalyzed polarity switch upon elimination of the polar functional group, whereas, the second monomer provides aqueous dissolution. The polymers of the present invention may be incorporated into negative resist compositions, which may also include photoacid generators, crosslinking agents, basic compounds, solvents, dissolution accelerators, photobase generators, latent basic compounds, surfactants, adhesion promoters, and anti-foaming agents.
The present invention provides polymers that are useful in negative resist compositions. Polymers of the present invention comprise (1) a first monomer having a polar functional group; (2) a second monomer; and optionally, (3) a third monomer that imparts at least one characteristic selected from crosslinkable functionality, etch resistance, and solubility modulation. The first monomer provides an acid catalyzed polarity switch upon elimination of the polar functional group, whereas, the second monomer provides aqueous dissolution. The polymers of the present invention may be incorporated into negative resist compositions, which may also include photoacid generators, crosslinking agents, basic compounds, solvents, dissolution accelerators, photobase generators, latent basic compounds, surfactants, adhesion promoters, and anti-foaming agents.
Photoacid generators have formula (1) wherein R.sup.1 and R.sup.2 are alkyl, or R.sup.1 and R.sup.2, taken together, may form a C.sub.4 C.sub.6 ring structure with sulfur, R is hydrogen or alkyl, R' is hydrogen, alkyl, alkoxyl or nitro, n is 1 to 6, and Y.sup.- is alkylsulfonate, arylsulfonate, bisalkylsulfonylimide or trisalkylsulfonylmethide. Chemically amplified resist compositions comprising the same have improved resolution, thermal stability, storage stability and minimized line edge roughness ##STR00001##
Chemically amplified photoresists with reduced outgassing or no outgassing may be used in a vacuum environment of a lithography tool, such as an extreme ultraviolet lithography tool. A chemically amplified photoresist has a photoacid generator molecule. When the photoacid generator is irradiated, an acid is generated. The acid reacts with a protecting group in the photoresist to form an open-ring structure with reduced outgassing or no outgassing.
