Pattern forming method
This invention provides a method for resist under layer film formation, which can form a resist under layer film which can function as an anti-reflection film, is excellent in pattern transfer properties and etching resistance, and does not cause bending of a pattern even in the transfer of a fined pattern, and a composition for the resist under layer film for use in the method, and a method for pattern formation. The method for resist under layer film formation comprises the steps of coating a composition for resist under layer film formation (for example, a composition comprising a compound having a phenolic hydroxyl group, a solvent, and an accelerator) onto a substrate to be processed, and treating the formed coating film under an oxidizing atmosphere having an oxygen concentration of not less than 1% by volume and a temperature of 300° C. or higher to form a resist under layer film.
1. A pattern forming method comprising:
coating a composition to form a resist under layer film on a substrate, said composition comprising a compound having a phenolic hydroxyl group and a solvent;
setting said composition under an oxidizing atmosphere with an oxygen content of 1% or more by volume and a temperature of 300 ° C. or higher to form a resist under layer film;
forming an intermediate layer on said resist under layer film, said intermediate layer including an inorganic oxide;
forming a resist film on said intermediate layer using a resist composition solution;
exposing necessary parts of the resist film to radiation;
developing the exposed resist film to form a resist pattern;
dry-etching said resist under layer film and said intermediate layer using said resist pattern as a mask; and
dry-etching said substrate using said resist under layer film and said intermediate layer as a mask.
2. The pattern forming method according to claim 1 , wherein said composition comprises at least one component selected from the group consisting of (a) a metal compound containing a metal element selected from the group consisting of elements of the groups 3 to 11 and elements of the groups 13 to 15 in the periodic table, (b) a peroxide, (c) a diazo compound, and (d) a halogen or a halogen acid, as an accelerator.
3. The pattern forming method according to claim 2 , wherein said peroxide (b) in said accelerator comprises at least one peroxide selected from the group consisting of a peroxy acid, a diacyl peroxide, a peroxy acid ester, a ketal peroxide, a peroxydicarbonate, a dialkyl peroxide, a ketone peroxide and an alkyl hydroxy peroxide.
4. The pattern forming method according to claim 2 , wherein said diazo compound (c) in said accelerator comprises 2,2′-azobisisobutylonitrile.
5. The pattern forming method according to claim 2 , wherein said metal compound (a) in said accelerator comprises at least one metal compound which contains a metal element selected from the group consisting of cerium, lead, silver, manganese, osmium, ruthenium, vanadium, thallium, copper, iron, bismuth and nickel.
6. The pattern forming method according to claim 2 , wherein said halogen or said halogen acid (d) in said accelerator comprises at least one halogen selected from the group consisting of chlorine, bromine and iodine, and at least one compound selected from the group consisting of a perhalogen acid, a halogen acid, a halous acid, a hypohalous acid, and salts of these acids.