Semiconductor device and method for manufacturing same

Abstract

The present invention reduces the effective dielectric constant of the interlayer insulating film while inhibiting the decrease of the reliability of the semiconductor device, which otherwise is caused by a moisture absorption. A copper interconnect comprising a Cu film 209 is formed in multilayer films comprising a L-Ox™ film 203 and a SiO 2 film 204. Since the L-Ox™ film 203 comprises ladder-shaped siloxane hydride structure, the film thickness and the film characteristics are stable, and thus changes in the film quality is scarcely occurred during the manufacturing process.

1 . A method for manufacturing a semiconductor device, comprising: 
 forming a first insulating film containing ladder-shaped siloxane hydride on a semiconductor substrate; and    forming a second insulating film adjacent to said first insulating film via a plasma CVD utilizing a source gas containing oxygen.    
   
   
       2 . The method according to  claim 1 , wherein said source gas contains a gas selected from a group consisting of O 2 , N 2 O, NO, CO, CO 2 , H 2 O, tetraethoxysilane (TEOS) and dimethylsilane.  
   
   
       3 . The method according to  claim 1 , wherein said source gas further comprises a silicon compound.  
   
   
       4 . The method according to  claim 3 , wherein said silicon compound is selected from a group consisting of SiH 4  (monosilane), monomethylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, tetraethoxysilane (TEOS) dimethyldimethoxysilane and tetravinylsilane.  
   
   
       5 . The method according to  claim 1 , wherein said second insulating film comprises a compound selected from the group consisting of SiO 2 , SiOC, SiON and SiOF.  
   
   
       6 . The method according to  claim 1 , further comprising: 
 after forming said second insulating film, selectively removing a multilayer films to form an interconnect groove, said multilayer films comprising said second insulating film and said first insulating film; and    filling said interconnect groove with a metal to form a metal interconnect.    
   
   
       7 . The method according to  claim 6 , wherein said ladder-shaped siloxane hydride is formed by being baked at a temperature within a range of from 200 degree C. to 400 degree C. during said forming said first insulating film.