Electric device and method for fabricating the same

Abstract

A wiring groove is formed in an insulating film, and then a reformed layer is formed in the vicinity of the wiring groove in the insulating film. Thereafter, a conductive film is buried in the wiring groove, thereby forming a wire. Subsequently, the reformed layer is removed to form a slit, and then a low-dielectric-constant film having a relative dielectric constant lower than the insulating film is buried in the slit.

1 . A method for fabricating an electric device, the method comprising the steps of: 
 depositing an insulating film over a substrate;    forming a wiring groove in the insulating film;    forming a reformed layer in part of the insulating film located in the vicinity of the wiring groove;    burying a conductive film in the wiring groove, thereby forming a wire, after the step of forming the reformed layer has been performed;    removing the reformed layer, thereby forming a slit, after the step of forming the wire has been performed; and    burying, in the slit, a low-dielectric-constant film having a relative dielectric constant lower than that of the insulating film.    
   
   
       2 . The method of  claim 1 , wherein the step of forming the reformed layer includes the step of reforming a surface portion of the insulating film.  
   
   
       3 . The method of  claim 2 , wherein the step of reforming the surface portion of the insulating film includes the step of exposing the surface portion of the insulating film to plasma.  
   
   
       4 . The method of  claim 2 , wherein the step of reforming the surface portion of the insulating film includes the step of oxidizing the surface portion of the insulating film.  
   
   
       5 . The method of  claim 1 , wherein the reformed layer is made of a material which is removable by wet etching.  
   
   
       6 . The method of  claim 1 , wherein the wiring groove includes: a plurality of first wiring grooves with relatively narrow spaces left therebetween; and a plurality of second wiring grooves with relatively wide spaces left therebetween, and 
 the step of forming the reformed layer includes the step of forming the reformed layer in the entire part of the narrow spaces between the first wiring grooves in the insulating film and in a part of the wide spaces between the second wiring grooves including the respective vicinities of the second wiring grooves in the insulating film.    
   
   
       7 . The method of  claim 1 , wherein the low-dielectric-constant film is a carbon-containing silicon oxide film, a carbon-containing silicon nitride film, a CDO film, an organic film, an HSQ film or an MSQ film.  
   
   
       8 - 9 . (canceled)