Pattern forming method and bilayer film

Abstract

A pattern forming method comprising forming a coating of a radiation-sensitive resin composition, which contains an acid-dissociable group-containing polysiloxane, alkali-insoluble or scarcely alkali-soluble but becoming alkali-soluble when the acid-dissociable group dissociates, on a film containing a polymer with a carbon content of 80 wt % or more and a polystyrene-reduced weight average molecular weight of 500-100,000, an applying radiation to the coating is provided. The method can form minute patterns with a high aspect ratio by suitably selecting a specific etching gas in the dry etching process, without being affected by standing waves.

1 - 4 . (canceled)  
     
     
         5 . A bilayer film comprising a film containing a polymer with a carbon content of 80 wt % or more and a polystyrene-reduced weight average molecular weight of 500-100,000 and a coated film applied thereon, wherein the coated film is formed from a radiation-sensitive resin composition containing an acid-dissociable group-containing polysiloxane which is alkali-insoluble or scarcely alkali-soluble but becomes alkali-soluble when the acid-dissociable group dissociates.  
     
     
         6 . The bilayer film according to  claim 5 , wherein the polymer with a carbon content of 80 wt % or more and a polystyrene-reduced weight average molecular weight of 500-100,000 contains a structural unit of the above formula (1).  
     
     
         7 - 9 . (canceled)  
     
     
         10 . The bilayer film according to  claim 5 , wherein the radiation-sensitive resin composition comprises an acid-dissociable group-containing polysiloxane and a radiation-sensitive photoacid generator.