Intermediate layer material of three-layer resist system and method of forming resist pattern

Claim 1

A method of forming a resist pattern, comprising the steps of: forming a bottom resist layer having a planar surface on a semiconductor substrate to be processed; forming, on said bottom resist layer, an intermediate layer comprising an organopolysiloxane expressed by a general formula (R.sub.3 SiO.sub.1/2).sub.m.(R.sub.2 SiO).sub.n.(RSiO.sub.3/2).sub.p.(SiO.sub.2).sub.q {where R is independently a hydrocarbon group or an alkoxy group; and m, n, p and q represent composition ratios of respective units and satisfy m+n+p+q=1, 1≧m>0, 1≧n≧0, 1≧p≧0, 1≧q≧0 (where p and q are not simultaneously 0), m/p≧0.3 (where p≠0), and/or m/q≦1 (where q≠0)}; forming a top resist layer of a radiation-sensitive organic polymeric material on said intermediate layer; forming a predetermined pattern in said top resist layer to obtain a top resist pattern; etching said intermediate layer using said top resist pattern as a mask to obtain an intermediate layer pattern; and etching said bottom resist layer using said intermediate layer pattern as a mask to obtain a bottom resist pattern.

Claim 2

A method of forming a resist pattern, comprising the steps of: forming a bottom resist layer having a planar surface on a semiconductor substrate to be processed; forming, on said bottom resist layer, an intermediate layer comprising an organopolysiloxane expressed by a general formula (R.sub.3 SiO.sub.1/2).sub.m.(R.sub.2 SiO).sub.n.(RSiO.sub.3/2).sub.p.(SiO.sub.2).sub.q {where R is independently a hydrocarbon group or an alkoxy group; and m, n, p and q represent composition ratios of respective units and satisfy m+n+p+q=1, 1≧m>0, 1≧n≧0, 1≧p≧0, 1≧q≧0 (where p and q are not simultaneously 0), m/p≧0.3 (where p≠0), and/or m/q≦1 (where q≠0)}; forming a top resist layer of a radiation-sensitive organic polymeric material on said intermediate layer; forming a predetermined pattern in said top resist layer to obtain a top resist pattern; etching said intermediate layer using said top resist pattern as a mask to obtain an intermediate layer pattern; and etching said bottom resist layer using said intermediate layer pattern as a mask to obtain a bottom resist pattern.