Method for forming resist pattern
A radiation-sensitive resin composition includes an acid-labile group-containing polymer and photoacid generator. The radiation-sensitive resin composition is used to form a resist pattern using a developer that includes an organic solvent in an amount of 80 mass % or more. The radiation-sensitive resin composition has a contrast value γ of 5.0 to 30.0. The contrast value γ is calculated from a resist dissolution contrast curve obtained when developing the radiation-sensitive resin composition using the organic solvent.
1. A method for forming a resist pattern, comprising:
using a radiation-sensitive resin composition, a developer that includes an organic solvent in an amount of 80 mass % or more, and an ArF excimer laser beam as an exposure light, the radiation-sensitive resin composition comprising:
(A) an acid-labile group-containing polymer;
(B) a radiation-sensitive acid generator; and
(D) an acid diffusion controller,
wherein the acid diffusion controller (D) is at least one compound selected from the group consisting of a hydroxy group-containing tri(cyclo)alkylamine, an amide group-containing compound and a photodegradable base, and
wherein a solubility of the radiation-sensitive resin composition to the organic solvent decreases upon the exposure to the ArF excimer laser, and a contrast value γ calculated from a resist dissolution contrast curve obtained by changing only a dose of the ArF excimer laser is 5.0 to 30.0.
2. The method for forming a resist pattern according to claim 1 , wherein the organic solvent is at least one organic solvent selected from the group consisting of alkyl carboxylates having 3 to 7 carbon atoms and dialkyl ketones having 3 to 10 carbon atoms.
3. The method for forming a resist pattern according to claim 1 , wherein the acid-labile group-containing polymer (A) includes a structural unit (I) shown by a formula (1) and a structural unit (II) shown by a formula (2),
wherein
R 1 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group,
R 2 represents a monovalent acid-labile group that is a linear or branched hydrocarbon group having 1 to 9 carbon atoms or an alicyclic group having 4 to 20 carbon atoms, wherein the alicyclic group is unsubstituted or at least one of the hydrogen atoms of the alicyclic group is substituted with a substituent,
R 3 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and
R 4 represents a monovalent non-acid-labile group that has an alicyclic structure and includes a polar group, wherein R 4 does not include a lactone-containing group or a cyclic carbonate-containing group.
4. The method for forming a resist pattern according to claim 3 , wherein R 4 represents a group that has a polyalicyclic structure, and that includes a carbonyl group, a hydroxyl group, or a cyano group as the polar group.
5. The method for forming a resist pattern according to claim 3 , wherein a content of the structural unit (II) in the acid-labile group-containing polymer (A) is from 1 to 30 mol %.
6. The method for forming a resist pattern according to claim 3 , wherein the acid-labile group-containing polymer (A) further includes a structural unit (III) that includes a lactone-containing group or a cyclic carbonate-containing group.