Film-forming composition, silicon-containing film, and resist pattern-forming method
A film-forming composition includes a compound including a Si—H bond and an orthoester. The compound preferably includes a structural unit that is a structural unit represented by formula (1-1), a structural unit represented by formula (1-2), or a combination thereof. In the formula (1-1) and the formula (1-2), R 1 and R 2 each represent a hydroxy group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms; and R 3 represents a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms that bonds to two Si atoms.
1. A resist pattern-forming method comprising:
applying a film-forming composition directly or indirectly on an upper face of a substrate to form a silicon-containing film;
applying a resist composition on an upper face of the silicon-containing film to form a resist film;
exposing the resist film; and
developing the resist film exposed, wherein
the film-forming composition comprises:
a polymer comprising a carbosilane structural unit represented by formula (1-2); and
an orthoester represented by formula (4):
wherein, in the formula (1-2), c is an integer of 1 to 3; R 2 represents a hydroxy group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms; d is an integer of 0 to 2, wherein in a case in which d is 2, two R 2 s are identical or different; R 3 represents a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms that bonds to two Si atoms; and p is an integer of 1 to 3, wherein in a case in which p is no less than 2, a plurality of R's are identical or different, and wherein a sum of c, d, and p is less than 4,
R 8 —C(OR 9 ) 3 (4)
wherein, in the formula (4), R 8 represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms; and each R 9 independently represents an unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
2. The resist pattern-forming method according to claim 1 , wherein an exposure light used in the exposing is an extreme ultraviolet ray or an electron beam.
3. The resist pattern-forming method according to claim 1 , further comprising carrying out etching after the developing.
4. The resist pattern-forming method according to claim 1 , further comprising, before the applying of the film-forming composition, forming an organic underlayer film directly or indirectly on the upper face of the substrate.
5. The resist pattern-forming method according to claim 1 , wherein the polymer further comprises a first structural unit that is a structural unit represented by formula (1-1),
wherein, in the formula (1-1), a is an integer of 1 to 3; R 1 represents a hydroxy group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms; and b is an integer of 0 to 2, wherein in a case in which b is 2, two R's are identical or different, and wherein a sum of a and b is no greater than 3.
6. The resist pattern-forming method according to claim 5 , wherein a total of an amount of the carbosilane structural unit and an amount of the first structural unit in the polymer is 30 to 90 mol % with respect to total structural units constituting the polymer.
7. The resist pattern-forming method according to claim 1 , wherein the polymer further comprises a second structural unit that is a structural unit represented by formula (2-1), a structural unit represented by formula (2-2), or a combination thereof,
wherein, in the formula (2-2), R 4 represents a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms that bonds to two Si atoms; and q is an integer of 1 to 4, wherein in a case in which q is no less than 2, a plurality of R 4 s are identical or different.
8. The resist pattern-forming method according to claim 7 , wherein the polymer further comprises a third structural unit that is a structural unit represented by formula (3-1), a structural unit represented by formula (3-2), or a combination thereof,
wherein,
in the formula (3-1), R 5 represents a hydroxy group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms; and e is an integer of 1 to 3, wherein in a case in which e is no less than 2, a plurality of R 5 s are identical or different, and
in the formula (3-2), R 6 represents a hydroxy group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms; f is 1 or 2, wherein in a case in which f is 2, two R 6 s are identical or different; R 7 represents a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms that bonds to two Si atoms; and r is an integer of 1 to 3, wherein in a case in which r is no less than 2, a plurality of R's are identical or different, and wherein a sum of f and r is no greater than 4.
9. The resist pattern-forming method according to claim 8 , wherein an amount of the third structural unit in the polymer is 5 to 60 mol % with respect to total structural units constituting the polymer.
10. The resist pattern-forming method according to claim 7 , wherein an amount of the second structural unit in the polymer is 5 to 70 mol % with respect to total structural units constituting the polymer.
11. The resist pattern-forming method according to claim 1 , wherein the polymer further comprises a third structural unit that is a structural unit represented by formula (3-1), a structural unit represented by formula (3-2), or a combination thereof,
wherein,
in the formula (3-1), R 5 represents a hydroxy group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms; and e is an integer of 1 to 3, wherein in a case in which e is no less than 2, a plurality of R 5 s are identical or different, and
in the formula (3-2), R 6 represents a hydroxy group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms; f is 1 or 2, wherein in a case in which f is 2, two R's are identical or different; R 7 represents a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms that bonds to two Si atoms; and r is an integer of 1 to 3, wherein in a case in which r is no less than 2, a plurality of R 7 s are identical or different, and wherein a sum of f and r is no greater than 4.
12. The resist pattern-forming method according to claim 11 , wherein an amount of the third structural unit in the polymer is 5 to 70 mol % with respect to total structural units constituting the polymer.
13. The resist pattern-forming method according to claim 1 , wherein the polymer has a weight average molecular weight of 1,000 to 100,000.
14. The resist pattern-forming method according to claim 13 , wherein the polymer has the weight average molecular weight of 1,500 to 3,000.
15. The resist pattern-forming method according to claim 1 , wherein the orthoester is at least one selected from the group consisting of an orthoformic acid ester, an orthoacetic acid ester, and an orthopropionic acid ester.
16. The resist pattern-forming method according to claim 1 , wherein an amount of the orthoester in the film-forming composition is 10 to 10,000 parts by mass with respect to 100 parts by mass of the polymer.
17. The resist pattern-forming method according to claim 1 , wherein an amount of the orthoester in the film-forming composition is 300 to 2,000 parts by mass with respect to 100 parts by mass of the polymer.
18. The resist pattern-forming method according to claim 1 , wherein an amount of the orthoester in the film-forming composition is 500 to 1,000 parts by mass with respect to 100 parts by mass of the polymer.
19. The resist pattern-forming method according to claim 1 , wherein the film-forming composition further comprises a solvent.
20. The resist pattern-forming method according to claim 1 , wherein the film-forming composition further comprises at least one of an acid generating agent and a basic compound.