Resist top coat composition and patterning process

1. A patterning process, comprising:

forming a photoresist film on a wafer;

forming a resist top coat on the photoresist film by using a resist top coat composition that contains a truxene compound having phenol groups shown by the following general formula (1):

wherein

R 1 , R 2 , and R 3 represent the same or different groups of a hydrogen atom; a hydroxyl group; a carboxyl group; a cyano group; a nitro group; an amino group; a halogen atom; or a linear, a branched, or a cyclic alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an acyloxy group;

each R 4 , R 5 , and R 6 represents a hydrogen atom, a hydroxyl group, or a substituted or an unsubstituted phenol group, or a naphthol group;

p, q, and r represent an integer of 1 to 5; and

s, t, and u represent an integer of 1 to 4; and

after exposure, developing the photoresist film.

2. The patterning process according to claim 1 , wherein the resist top coat composition is soluble in an alkaline developer.

3. The patterning process according to claim 2 , wherein the resist top coat composition contains an organic solvent which is a mixture of an alcohol solvent with an ether solvent or with an aromatic solvent.

4. The patterning process according to claim 3 , wherein the exposure is performed under vacuum.

5. The patterning process according to claim 2 , wherein the exposure is performed under vacuum.

6. The patterning process according to claim 1 , wherein the resist top coat composition contains an organic solvent which is a mixture of an alcohol solvent with an ether solvent or with an aromatic solvent.

7. The patterning process according to claim 6 , wherein the exposure is performed under vacuum.

8. The patterning process according to claim 1 , wherein the exposure is performed under vacuum.

9. The patterning process according to claim 1 , wherein the exposure is performed by using a light with a wavelength of 3 to 15 nm, or an electron beam.

10. The patterning process according to claim 1 , wherein the developing of the photoresist film comprises:

developing the photoresist film by an alkaline developer; and

removing the resist top coat.

11. The patterning process according to claim 1 , wherein the photoresist film formed on the wafer has a base resin of a polymer having an average molecular weight of 1000 to 500000 and comprising repeating units a1 and a2 shown by the following general formula (2) and repeating units b1 and b2 shown by the following general formula (3):

wherein

in the general formula (2),

each R 7 and R 9 independently represents a hydrogen atom or a methyl group;

R 8 and R 10 represent an acid labile group;

X 1 represents a connecting group having 1 to 14 carbon atoms and having any one, or two or more of a single bond, an ester group, a lactone ring, a phenylene group, and a naphthylene group;

X 2 represents a single bond, an ester group, or an amide group; and

in the general formula (3),

each R 11 and R 15 independently represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group;

R 12 , R 13 , R 14 , R 16 , R 17 , and R 18 represent the same or different linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms and optionally containing a carbonyl group, an ester group, or an ether group, or an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a thiophenyl group;

Z 0 represents a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, —O—R 19 —, or —C(═O)—Z 1 —R 19 —; and

Z 1 represents an oxygen atom or NH; R 19 represents a linear, a branched, or a cyclic alkylene group, a phenylene group, or an alkenylene group having 1 to 13 carbon atoms wherein these groups may optionally contain a carbonyl group, an ester group, an ether group, or a hydroxyl group, or may be optionally fluorine-substituted; and

each repeating unit satisfies: 0≦a1≦0.9, 0≦a2≦0.9, 0<a1+a2<1, 0≦b1≦0.3, 0≦b2≦0.3, 0<b1+b2≦0.3, and 0<a1+a2+b1+b2≦1.