Etching method

Abstract

An interlayer insulating film composed of an organic compound film containing an organic component as a main constituent is deposited on a semiconductor substrate. Then, etching is performed with respect to the interlayer insulating film by using a plasma derived from an etching gas containing an ammonia gas as a main constituent. As a result, active hydrogen is generated in the plasma derived from the ammonia gas to decompose the organic component into hydrogen cyanide, whereby etching proceeds. Since a surface of the organic compound film is efficiently nitrided by nitrogen generated from the ammonia gas, the sidewalls of a depressed portion in the organic compound film are protected so that an excellent anisotropic property is provided. Since the etching gas does not contain a component which oxidizes the organic compound film, the problem does not occur that a gas is generated from the organic compound film in a subsequent heat treatment process.

What is claimed is:  
     
         1 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing an ammonia gas and a fluorine gas as main constituents.  
     
     
         2 . The etching method of  claim 1 , wherein said etching gas contains an inert gas.  
     
     
         3 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing a hydrogen gas, a nitrogen gas, and a fluorine gas as main constituents.  
     
     
         4 . The etching method of  claim 3 , wherein said etching gas contains an inert gas.  
     
     
         5 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing a hydrogen gas and a nitrogen trifluoride gas as main constituents.  
     
     
         6 . The etching method of  claim 5 , wherein said etching gas contains an inert gas.  
     
     
         7 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing a nitrogen gas and a hydrogen fluoride gas as main constituents.  
     
     
         8 . The etching method of  claim 7 , wherein said etching gas contains an inert gas.  
     
     
         9 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing a nitrogen gas and a fluorinated hydrocarbon gas as main constituents.  
     
     
         10 . The etching method of  claim 9 , wherein said etching gas contains an inert gas.  
     
     
         11 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing a carbon dioxide gas and a fluorine gas as main constituents.  
     
     
         12 . The etching method of  claim 11 , wherein said etching gas contains an inert gas.  
     
     
         13 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing a carbon dioxide gas and a fluorinated hydrocarbon gas as main constituents.  
     
     
         14 . The etching method of  claim 13 , wherein said etching gas contains an inert gas.  
     
     
         15 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing a carbon monoxide gas and a fluorine gas as main constituents.  
     
     
         16 . The etching method of  claim 15 , wherein said etching gas contains an inert gas.  
     
     
         17 . An etching method comprising the step of performing anisotropic etching with respect to an interlayer insulating film composed of an organic-inorganic hybrid film containing an organic component and a silica component as main constituents by using a plasma derived from an etching gas containing a carbon monoxide gas and a fluorinated hydrocarbon gas as main constituents.  
     
     
         18 . The etching method of  claim 17 , wherein said etching gas contains an inert gas.