Composition for forming resist underlayer film and pattern-forming method

1. A composition for forming a resist underlayer film, comprising:

a polysiloxane;

an acid diffusion controller; and

a solvent comprising:

an organic solvent having a standard boiling point of no less than 150.0° C.; and

water,

wherein a content of the organic solvent is no less than 1% by mass and no greater than 50% by mass with respect to a total amount of the solvent, and

a content of water is no less than 1% by mass and no greater than 30% by mass with respect to the total amount of the solvent.

2. The composition according to claim 1 , wherein the standard boiling point of the organic solvent is no less than 180° C.

3. The composition according to claim 1 , wherein the organic solvent is an ester, an alcohol, an ether or a combination thereof.

4. The composition according to claim 1 , wherein the organic solvent is a lactone, a carbonate, a compound represented by formula (B-1), or a combination thereof,

wherein, in the formula (B-1), R 1 and R 2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an acyl group having 1 to 4 carbon atoms; R 3 represents a hydrogen atom or a methyl group; n is an integer of 1 to 4, in a case where R 3 is present in a plurality of number, a plurality of R a s are each a same or different.

5. The composition according to claim 1 , wherein a relative permittivity of the organic solvent is 13 or greater and 200 or less.

6. The composition according to claim 1 , wherein the solvent further comprises an alcohol other than the organic solvent.

7. The composition according to claim 1 , wherein the polysiloxane is a hydrolytic condensate of a compound comprising a hydrolyzable silane compound represented by formula (i):

R A a SiX 4-a   (i)

wherein, in the formula (i), R A represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms or a cyano group, wherein a part or all of hydrogen atoms included in the alkyl group represented by R A are not substituted or substituted by an epoxyalkyloxy group, an epoxy group, an acid anhydride group or a cyano group, and a part or all of hydrogen atoms included in the aryl group represented by R A are not substituted or substituted by a hydroxy group; X represents a halogen atom or —OR B , wherein R B represents a monovalent organic group; a is an integer of 0 to 3, wherein in a case where R A and X are each present in a plurality of number, a plurality of R A s are each a same or different and a plurality of Xs are each a same or different.

8. A pattern-forming method comprising:

providing a resist underlayer film on a substrate using the composition according to claim 1 ;

providing a resist film on the resist underlayer film using a resist composition;

exposing the resist film by irradiation with a radioactive ray through a mask;

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.

9. The composition according to claim 1 , wherein the acid diffusion controller comprises an amine compound, an amide group-containing compound, a urea compound, a nitrogen-containing heterocyclic compound, or a combination thereof.

10. The composition according to claim 1 , wherein the acid diffusion controller comprises an amide group-containing compound.

11. The composition according to claim 1 , wherein the acid diffusion controller comprises an onium salt compound which is degraded upon exposure to light to lose basicity.

12. The composition according to claim 1 , wherein a content of the acid diffusion controller with respect to a total solid content in the composition is no less than 1% by mass and no greater than 20% by mass.

13. The composition according to claim 1 , wherein a content of the acid diffusion controller with respect to a total solid content in the composition is no less than 2% by mass and no greater than 10% by mass.