Resist underlayer film forming composition that contains novolac resin having polynuclear phenol
There is provided a composition for forming a resist underlayer film which has high dry-etching resistance and wiggling resistance, and achieves excellent planarizing properties for a semiconductor substrate surface having level differences or irregular portions. A resist underlayer film-forming composition including a phenol novolac resin that is obtained by causing a compound that has at least three phenolic groups, in which each of the phenolic groups has a structure bonded to a tertiary carbon atom or has a structure bonded to a quaternary carbon atom to which a methyl group binds, to react with an aromatic aldehyde or an aromatic ketone in the presence of an acid catalyst. The phenol novolac resin preferably contains a unit structure of Formula (1), a unit structure of Formula (2), a unit structure of Formula (3), a unit structure of Formula (4), or a combination of these unit structures:
1. A resist underlayer film-forming composition comprising:
a solvent; and
a phenol novolac resin that is obtained by causing a compound that has at least three phenolic groups, in which each of the phenolic groups has a structure bonded to a tertiary carbon atom or has a structure bonded to a quaternary carbon atom to which a methyl group binds, to react with an aromatic aldehyde or an aromatic ketone in the presence of an acid catalyst.
2. The resist underlayer film-forming composition according to claim 1 , wherein:
the phenol novolac resin contains a unit structure of Formula (1), a unit structure of Formula (2), a unit structure of Formula (3), a unit structure of Formula (4), or a combination of these unit structures:
where:
A is an organic group having at least three phenolic groups, in which each of the phenolic groups has a structure bonded to a tertiary carbon atom, and each of B 1 , B 2 , B 3 , and B 4 is Formula (5):
where:
C 1 is a C 6-40 aryl group or a heterocyclic group that is optionally substituted with a halogen group, a nitro group, an amino group, or a hydroxy group;
C 2 is a hydrogen atom or a C 1-10 alkyl group, a C 6-40 aryl group, or a heterocyclic group each of which is optionally substituted with a halogen group, a nitro group, an amino group, or a hydroxy group; and
C 1 and C 2 optionally form a ring together with a carbon atom bonded to C 1 and C 2 .
3. The resist underlayer film-forming composition according to claim 2 , wherein:
A is Formula (6):
where:
T is a single bond, a C 1-10 alkylene group, or a C 6-40 arylene group;
X 1 and X 2 each are a hydrogen atom or a methyl group;
R 1 to R 4 each are a hydrogen atom or a C 1-10 alkyl group;
R 5 to R 8 each are a C 1-10 alkyl group or a C 6-40 aryl group;
n1 to n4 each are an integer of 0 to 3; and
each of the phenolic groups binds to B 1 , B 2 ,B 3 , and B 4 .
4. The resist underlayer film-forming composition according to claim 2 , wherein:
A is Formula (7):
where:
R 9 to R 11 each are a hydrogen atom or a C 1-10 alkyl group;
R 12 to R 14 each are a C 1-10 alkyl group or a C 6-40 aryl group;
X 3 is a hydrogen atom or a methyl group;
n5 to n7 each are an integer of 0 to 3; and
each of the phenolic groups binds to B 1 , B 2 , B 3 , and B 4 .
5. The resist underlayer film-forming composition according to claim 2 , wherein C 1 is an anthryl group or a pyrenyl group.
6. The resist underlayer film-forming composition according to claim 1 , further comprising a cross-linking agent.
7. The resist underlayer film-forming composition according to claim 1 , further comprising an acid and/or an acid generator.
8. A resist underlayer film obtained by applying the resist underlayer film-forming composition as claimed in claim 1 onto a semiconductor substrate and baking the resist underlayer film-forming composition.
9. A method for forming an underlayer film used in production of a semiconductor, the method comprising:
applying the resist underlayer film-forming composition as claimed in claim 1 onto a semiconductor substrate and baking the resist underlayer film-forming composition to form an underlayer film.
10. A method for producing a semiconductor device, the method comprising:
forming an underlayer film on a semiconductor substrate using the resist underlayer film-forming composition as claimed in claim 1 ;
forming a resist film on the underlayer film;
forming a resist pattern by irradiation with light or an electron beam and development;
etching the underlayer film using the resist pattern; and
processing the semiconductor substrate using the underlayer film patterned.
11. A method for producing a semiconductor device, the method comprising:
forming an underlayer film on a semiconductor substrate using the resist underlayer film-forming composition as claimed in claim 1 ;
forming a hard mask on the underlayer film;
further forming a resist film on the hard mask;
forming a resist pattern by irradiation with light or an electron beam and development;
etching the hard mask using the resist pattern;
etching the underlayer film using the hard mask patterned; and
processing the semiconductor substrate using the underlayer film patterned.
12. The method for producing the semiconductor device according to claim 11 , wherein the hard mask is formed by evaporation of an inorganic substance.