Composition for resist underlayer film formation, resist underlayer film and method for producing patterned substrate

1. A method for producing a patterned substrate, comprising:

forming a resist underlayer film from a composition directly or indirectly on an upper face side of a substrate;

forming a resist pattern directly or indirectly on an upper face side of the resist underlayer film; and

forming a pattern on the substrate by etching the substrate a plurality of times using the resist pattern as a mask,

wherein the composition includes a solvent, and a compound including a group of formula (1),

*—R 1 —R 2 —CN  (1)

where R 1 is a single bond or an oxygen atom, R 2 is a divalent chain or alicyclic hydrocarbon group having 1 to 30 carbon atoms, and * is a bonding site directly bonding to an aromatic ring in the compound, and the compound is selected from the group consisting of a novolac resin, a resol resin, an aromatic ring-containing vinyl resin, an acenaphthylene resin, an indene resin, a polyarylene resin, a triazine resin, a pyrene resin, a calixarene resin, an aromatic ring-containing compound having a molecular weight of no less than 200 and no greater than 3,000, and a combination thereof.

2. The method of claim 1 , wherein the group is one of a cyanomethyl group, a cyanoethyl group, a cyanopropyl group, a cyanobutyl group, a cyanopentyl group, a cyanohexyl group, a cyanooctyl group, a cyanodecyl group, a cyanomethyloxy group, a cyanoethyloxy group, a cyanopropyloxy group, a cyanobutyloxy group, a cyanopentyloxy group, a cyanohexyloxy group, a cyanooctyloxy group, and a cyanodecyloxy group.

3. The method of claim 1 , wherein the compound is a novolac resin, a resol resin, or a combination thereof.

4. The method of claim 1 , wherein the compound includes an aromatic ring at a proportion of 20% by mass or more.

5. The method of claim 1 , wherein the compound includes an aromatic ring at a proportion of 30% by mass or more.

6. The method of claim 1 , wherein the compound includes an aromatic ring at a proportion of 40% by mass or more.

7. The method of claim 4 , wherein the group is one of a cyanomethyl group, a cyanoethyl group, a cyanomethyloxy group, and a cyanoethyloxy group.

8. The method of claim 1 , wherein the compound includes at least one polycondensation resin.

9. The method of claim 1 , wherein the compound is at least one polycondensation resin.

10. The method of claim 2 , wherein the compound includes an aromatic ring at a proportion of 20% by mass or more.

11. The method of claim 2 , wherein the compound includes an aromatic ring at a proportion of 30% by mass or more.

12. The method of claim 2 , wherein the compound includes an aromatic ring at a proportion of 40% by mass or more.

13. The method of claim 1 , wherein the compound is an aromatic ring-containing vinyl resin, an acenaphthylene resin, an indene resin, a polyarylene resin, a triazine resin, a pyrene resin, a calixarene resin or a combination thereof.

14. The method of claim 1 , wherein the group is one of a cyanomethyloxy group and a cyanoethyloxy group.

15. The method of claim 4 , wherein the group is one of a cyanomethyloxy group and a cyanoethyloxy group.

16. The method of claim 3 , wherein the compound includes an aromatic ring at a proportion of 20% by mass or more.

17. The method of claim 8 , wherein the compound includes an aromatic ring at a proportion of 20% by mass or more.

18. The method of claim 9 , wherein the compound includes an aromatic ring at a proportion of 20% by mass or more.

19. The method of claim 13 , wherein the compound includes an aromatic ring at a proportion of 20% by mass or more.

20. The method of claim 14 , wherein the compound includes an aromatic ring at a proportion of 20% by mass or more.