Photoresist compositions and methods of forming photolithographic patterns
Provided are photoresist compositions useful in forming photolithographic patterns by a negative tone development process. Also provided are methods of forming photolithographic patterns by a negative tone development process and substrates coated with the photoresist compositions. The photoresist compositions include one or more polymer additive that contains a basic moiety and which is substantially non-miscible with a resin component of the resist. The compositions, methods and coated substrates find particular applicability in the manufacture of semiconductor devices.
1. A photoresist composition, comprising:
a first polymer comprising an acid labile group;
a second polymer comprising:
a first unit formed from a first monomer having the following general formula (I):
wherein: P is a polymerizable functional group; R 1 is chosen from substituted and unsubstituted C1 to C20 linear, branched and cyclic hydrocarbons; Z is a spacer unit chosen from substituted and unsubstituted linear or branched aliphatic and aromatic hydrocarbons, and combinations thereof, optionally with one or more linking moiety chosen from —O—, —S— and —COO—; and n is an integer from 0 to 5; and
a second unit formed from a second monomer having a basic moiety and a vinyl polymerizable group, wherein the first monomer and the second monomer are different;
wherein the second polymer is insoluble in alkaline developer, is free of acid-labile groups, and has a surface energy lower than a surface energy of the first polymer;
a photoacid generator; and
a solvent.
2. The photoresist composition of claim 1 , wherein the basic moiety is chosen from amines.
3. The photoresist composition of claim 1 , wherein the basic moiety is chosen from amides.
4. A coated substrate, comprising a substrate and a layer of a photoresist composition of claim 1 over a surface of the substrate.
5. A method of forming a photolithographic pattern by negative tone development, comprising:
(a) providing a substrate comprising one or more layer to be patterned over a surface of the substrate;
(b) applying a layer of a photoresist composition of claim 1 over the one or more layer to be patterned;
(c) patternwise exposing the photoresist composition layer to actinic radiation;
(d) heating the exposed photoresist composition layer in a post-exposure bake process; and
(e) applying a developer comprising an organic solvent to the photoresist composition layer, wherein unexposed portions of the photoresist layer are removed by the developer, leaving a photoresist pattern over the one or more layer to be patterned.
6. The method of claim 5 , wherein the patternwise exposing is conducted by immersion lithography.
7. A photoresist composition, comprising:
a first polymer comprising an acid labile group;
a second polymer comprising:
a first unit formed from a first monomer having the following general formula (I):
wherein: P is a polymerizable functional group; R 1 is chosen from substituted and unsubstituted C1 to C20 linear, branched and cyclic hydrocarbons; Z is a spacer unit chosen from substituted and unsubstituted linear or branched aliphatic and aromatic hydrocarbons, and combinations thereof, optionally with one or more linking moiety chosen from —O—, —S— and —COO—; and n is an integer from 0 to 5; and
a second unit formed from a second monomer having a basic moiety and an allyl polymerizable group, wherein the first monomer and the second monomer are different;
wherein the second polymer is insoluble in alkaline developer, is free of acid-labile groups, and has a surface energy lower than a surface energy of the first polymer;
a photoacid generator; and
a solvent.