Silicon-containing film forming composition, silicon-containing film serving as etching mask, substrate processing intermediate, and substrate processing method

A silicon-containing film serving as an etching mask, said film being formed from a silicon-containing film forming composition used for a multilayer resist process comprising the steps of forming in sequence an undercoat film, an intermediate silicon-containing film, and a photoresist film on a patternable substrate and effecting etching in multiple stages,

• said silicon-containing film forming composition for use in forming the intermediate silicon-containing film serving as an etching mask, comprising a silicon-containing polymer, an acid generator, and a crosslinker, said silicon-containing polymer is obtained through hydrolytic condensation of a mixture of hydrolysable silanes comprising:
• at least one silicon-silicon bond-containing silane compound having the general formula (1):
• R(6-m)Si2Xm (1)
• wherein each R is independently a substituted or unsubstituted monovalent hydrocarbon group of 1 to 12 carbon atoms, each X is independently an alkoxy group, alkanoyloxy group or halogen atom, and m is a number from 3 to 6, and
• a hydrolysable silane compound having the general formula (2):
• AaSiB(4-a) (2)
• wherein each A is independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 12 carbon atoms, each B is independently an alkoxy group, alkanoyloxy group or halogen atom, and a is 0 or 1, and
• said silicon-containing film being formed between the undercoat film and the resist film on the patternable substrate, with or without another interleaf film.

A substrate process intermediate comprising in sequence:

• a patternable substrate, an undercoat film, a silicon-containing film, and a photoresist film,
• said silicon-containing film being formed from a silicon-containing film forming composition used for a multilayer resist process comprising the steps of forming in sequence an undercoat film, an intermediate silicon-containing film, and a photoresist film on a patternable substrate, and effecting etching in multiple stages,
• said silicon-containing film forming composition for use in forming the intermediate silicon-containing film serving as an etching mask, comprising a silicon-containing polymer, an acid generator, and a crosslinker, said silicon-containing polymer is obtained through hydrolytic condensation of a mixture of hydrolysable silanes comprising:
• at least one silicon-silicon bond-containing silane compound having the general formula (1):
• R(6-m)Si2Xm (1)
• wherein each R is independently a substituted or unsubstituted monovalent hydrocarbon group of 1 to 12 carbon atoms, each X is independently an alkoxy group, alkanoyloxy group or halogen atom, and m is a number from 3 to 6, and
• a hydrolysable silane compound having the general formula (2):
• AaSiB(4-a) (2)
• wherein each A is independently hydrogen or a substituted or unsubstituted monovalent hydrocarbon group of 1 to 12 carbon atoms, each B is independently an alkoxy group, alkanoyloxy group or halogen atom, and a is 0 or 1.