Composition for forming silicon-containing resist underlayer film and patterning process

1. A composition for forming a silicon-containing resist underlayer film comprising:

a thermosetting silicon-containing material containing any one or more of a repeating unit shown by the following general formula (Sx-1), a repeating unit shown by the following general formula (Sx-2), and a partial structure shown by the following general formula (Sx-3):

wherein:

R 1 represents an organic group having one or more silanol groups, hydroxy groups, or carboxy groups, or an organic group from which a protecting group is eliminated by an action of acid and/or heat to generate one or more silanol groups, hydroxy groups, or carboxy groups; and

R 2 and R 3 are each independently the same as R 1 or each represent a hydrogen atom or a monovalent substituent having 1 to 30 carbon atoms; and

a compound shown by the following general formula (P-0):

wherein in the formula (P-0),

R 100 represents a divalent organic group substituted with one or more fluorine atoms;

R 101 and R 102 each independently represents a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms substituted or unsubstituted with a hetero atom selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom;

R 103 represents a linear, branched, or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms substituted or unsubstituted with a hetero atom selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom;

R 101 and R 102 , or R 101 and R 103 , are optionally bonded to each other to form a ring with a sulfur atom in the formula; and

L 104 represents a single bond or a linear, branched, or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms substituted or unsubstituted with a hetero atom selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom.

2. The composition for forming a silicon-containing resist underlayer film according to claim 1 , further comprising a crosslinking catalyst selected from the group consisting of a sulfonium salt represented by the following general formula (Xc-1), an iodonium salt, a phosphonium salt, an ammonium salt and a polysiloxane having a structure partially containing one of these salts or an alkaline metal salt,

wherein:

R 204 , R 205 , and R 206 may be identical to or different from one another and each represent a linear, branched, or cyclic alkyl group, alkenyl group, oxoalkyl group, or oxoalkenyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or an aralkyl group or aryloxoalkyl group having 7 to 12 carbon atoms, and some or all of the hydrogen atoms of these groups are optionally substituted with an alkoxy group;

R 205 and R 206 may form a ring, and when a ring is formed, R 205 and R 206 each represent an alkylene group having 1 to 6 carbon atoms; and

A − represents a non-nucleophilic counter ion.

3. The composition for forming a silicon-containing resist underlayer film according to claim 2 , further comprising a nitrogen-containing compound having an acid-decomposable substituent.

4. The composition for forming a silicon-containing resist underlayer film according to claim 1 , further comprising a nitrogen-containing compound having an acid-decomposable substituent.