Composition for forming upper layer film for immersion exposure, upper layer film for immersion exposure, and method of forming photoresist pattern
The object of the invention is to provide a composition for forming an upper layer film for immersion exposure capable of forming an upper layer film effectively inhibited from developing defects through an immersion exposure process, such as a watermark defect and dissolution residue defect. Also provided are an upper layer film for immersion exposure and a method of forming a resist pattern. The composition for forming an upper layer film includes a resin ingredient and a solvent. The resin ingredient includes a resin (A) having at least one kind of repeating units selected among those represented by the formulae (1-1) to (1-3) and at least either of the two kinds of repeating units represented by the formulae (2-1) and (2-2). (1-1) (1-2) (1-3) (2-1) (2-2) [In the formulae, R 1 represents hydrogen or methyl; R 2 and R 3 each represents methylene, linear or branched C 2-6 alkylene, or alicyclic C 4-12 alkylene; R 4 represents hydrogen or methyl; and R 5 represents a single bond, methylene, or linear or branched C 2-6 alkylene.].
1. A composition for forming an upper layer film in liquid immersion lithography comprising:
a resin component; and
a solvent, said resin component comprising a resin (A) having a repeating unit represented by the following formula (1-1) and a repeating unit represented by the following formula (2-1),
wherein, in the general formula (1-1), R 1 is a hydrogen atom or a methyl group, R 2 and R 3 each individually are a methylene group, a linear or branched alkylene group having 2 to 6 carbon atoms, or an alicyclic alkylene group having 4 to 12 carbon atoms,
wherein, in the general formula (2-1), R 4 is a hydrogen atom or a methyl group, and R 5 is a single bond, a methylene group, or a linear or branched alkylene group having 2 to 6 carbon atoms,
wherein said resin component further comprises a resin (B) having a repeating unit represented by the following formula (3-1), a repeating unit represented by the following formula (3-2), a repeating unit represented by the following formula (3-3) or a combination thereof, and having a repeating unit represented by the following formula (4), said resin (B) forming a film having a receding contact angle with water of 65° or more,
wherein, in the general formulae (3-1) to (3-3), R 6 individually is a hydrogen atom, a methyl group, or a trifluoromethyl group, R 6′ is a linear or branched alkyl group having 1 to 3 carbon atoms with at least one hydrogen atom being substituted by a fluorine atom, R 7 individually is a single bond, a methylene group, a linear or branched alkylene group having 2 to 6 carbon atoms, or an alicyclic alkylene group having 4 to 12 carbon atoms, R 8 is a linear or branched alkyl group having 1 to 10 carbon atoms with at least one hydrogen atom being substituted by a fluorine atom or an alicyclic alkyl group having 3 to 10 carbon atoms with at least one hydrogen atom being substituted by a fluorine atom, and A represents a single bond, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group,
wherein, in the general formula (4), R 9 is a hydrogen atom, a methyl group, or a trifluoromethyl group, and R 10 is a single bond, a methylene group, or a linear or branched alkylene group having 2 to 6 carbon atoms.
2. The composition for forming an upper layer film in liquid immersion lithography according to claim 1 , wherein said resin (A) forms a film having a receding contact angle with water of less than 60°.
3. The composition for forming an upper layer film in liquid immersion lithography according to claim 1 ,
wherein said resin (B) comprises said repeating unit represented by the general formula (3-1) and said repeating unit represented by the general formula (4-1).
4. The composition for forming an upper layer film in liquid immersion lithography according to claim 1 , wherein the content of said resin (A) is in the range from 5% to 70% by weight based on 100% by weight of the total of said resin component.
5. An upper layer film in liquid immersion lithography characterized in that said film is formed using said composition for forming an upper layer film in liquid immersion lithography according to claim 1 .
6. A method for forming a photoresist pattern characterized by comprising:
(1) applying a photoresist composition to a substrate to form a photoresist film;
(2) applying said composition for forming an upper layer film in liquid immersion lithography according to claim 1 to said photoresist film to form an upper layer film; and
(3) disposing a liquid immersion medium between said upper layer film and a lens, irradiating said photoresist film and said upper layer film with exposure light through said liquid immersion medium and a mask having a specific pattern, and developing said photoresist film to obtain a photoresist pattern.