Resist underlayer film-forming composition and method for forming pattern
A resist underlayer film-forming composition includes a polymer including a structural unit shown by a formula (1), and having a polystyrene-reduced weight average molecular weight of from 3000 to 10000, and a solvent. Each of R 3 to R 8 independently represents a group shown by a formula (2), a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, or a glycidyl ether group having 3 to 6 carbon atoms, wherein at least one of R 3 to R 8 represents the group shown by the formula (2).
1. A resist underlayer film-forming composition comprising:
a polymer comprising a structural unit shown by a formula (1), and having a polystyrene-reduced weight average molecular weight of from 3000 to 10000; and
a solvent,
wherein
each of R 3 to R 8 independently represents a group shown by a formula (2), a hydrogen atom, a hydroxyl group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxycarbonyl group having 2 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, or a substituted or unsubstituted glycidyl ether group having 3 to 6 carbon atoms, wherein at least one of R 3 to R 8 represents the group shown by the formula (2), and
X represents a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkanediyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkanediyloxy group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkanediyloxy group having 3 to 20 carbon atoms, a substituted or unsubstituted arenediyl group having 6 to 14 carbon atoms, or a divalent group formed by an arbitrary combination thereof,
wherein
R 1 represents a single bond, a substituted or unsubstituted alkanediyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted arenediyl group having 6 to 20 carbon atoms, and
R 2 represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.
2. The resist underlayer film-forming composition according to claim 1 , wherein the polymer has a dispersity of 1.4 to 5.0.
3. The resist underlayer film-forming composition according to claim 1 , further comprising an acid generator.
4. The resist underlayer film-forming composition according to claim 1 , further comprising a crosslinking agent.
5. The resist underlayer film-forming composition according to claim 1 , the resist underlayer film-forming composition being used to form a pattern on a non-planar substrate.
6. A method for forming a pattern comprising:
providing a resist underlayer film on a substrate using the resist underlayer film-forming composition according to claim 1 ;
providing a resist film on the resist underlayer film using a resist composition;
exposing the resist film by applying exposure light to the resist film through a photomask;
developing the exposed resist film to form a resist pattern; and
sequentially dry-etching the resist underlayer film and the substrate using the resist pattern as a mask.
7. The method according to claim 6 , wherein the substrate is a non-planar substrate.