Negative resist composition, method of forming resist pattern, and complex
A negative resist composition including a complex represented by the general formula (1); and a polymerization initiator. in which M represents hafnium (Hf) or zirconium (Zr), X represents a ligand including a conjugate base of an acid which has an acid dissociation constant (pKa) of 3.8 or less and has a polymerizable group, Y represents a ligand having no polymerizable group, and n represents an integer of 1 to 4. [MX n Y 4-n ] (1)
1. A negative resist composition comprising:
a complex represented by the following general formula (1):
[MX n Y 4-n ] (1)
wherein M represents hafnium (Hf) or zirconium (Zr), X represents a ligand comprising a conjugate base of an acid which has an acid dissociation constant (pKa) of 3.8 or less and has a polymerizable group, Y represents a ligand having no polymerizable group, and n represents an integer of 1 to 4;
a polymerization initiator; and
an organic solvent.
2. A method of forming a resist pattern, comprising: forming a resist film on a substrate using the negative resist composition of claim 1 ; conducting exposure of the resist film; and developing the resist film after the exposure to form a resist pattern.
3. The negative resist composition according to claim 1 , wherein the acid dissociation constant (pKa) of the acid is 2.8 or less.
4. The negative resist composition according to claim 1 , wherein X in the formula (1) is a ligand comprising a conjugate base represented by general formula (2) shown below:
R 1 —Y 1 —SO 3 θ (2)
wherein, in formula (2), R 1 represents a polymerizable group having a group selected from groups respectively represented by formulae (X-01) to (X-07) shown below, and Y 1 represents a divalent linking group or a single bond;
wherein R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms, Ar represents an aromatic hydrocarbon group, n represents an integer of 0 to 2, and * represents a valence bond.
5. The negative resist composition according to claim 1 , wherein X in the formula (1) is a ligand comprising a conjugate base selected from the group consisting of a conjugate base of 3-(methacryloyloxy)-1-propanesulfonic acid, a conjugate base of 3-(acryloyloxy)-1-propanesulfonic acid, a conjugated base of vinylsulfonic acid, and a conjugated base of styrenesulfonic acid.
6. The negative resist composition according to claim 1 , wherein X in the formula (1) is a ligand comprising a conjugate base represented by general formula (3) shown below:
R 2 —Y 2 —COO θ (3)
wherein, in formula (3), R 2 represents a polymerizable group having a group selected from groups respectively represented by formulae (X-01) to (X-07) shown below, and Y 2 represents a divalent linking group or a single bond:
wherein R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms, Ar represents an aromatic hydrocarbon group, n represents an integer of 0 to 2, and * represents a valence bond.
7. The negative resist composition according to claim 1 , wherein X in the formula (1) is a ligand comprising a conjugate base selected from the group consisting of a conjugate base of carboxymethyl methacrylate, and a conjugate base of carboxymethyl acrylate.
8. The negative resist composition according to claim 1 , wherein M represents hafnium (Hf).
9. The negative resist composition according to claim 1 , wherein M represents zirconium (Zr).
10. The method according to claim 2 , wherein the resist film is exposed with EB or EUV.