Method of manufacturing a semiconductor device

Abstract

A method of manufacturing a semiconductor device according to an embodiment, includes forming a wiring in a surface of a first insulating film on a semiconductor substrate, exposing the first insulating film in whose surface the wiring is formed to a plasma containing a rare gas so as to form a densified layer on the surface of the first insulating film, removing an oxide film formed on the wiring, after the densified layer is formed and forming a second insulating film on the wiring from which the oxide film is removed and on the densified layer, wherein the processes from the removal of the oxide film to the formation of the second insulating film are carried out without being atmospherically-exposed.

1 . A method of manufacturing a semiconductor device, comprising:
 forming a wiring in a surface of a first insulating film on a semiconductor substrate;   exposing the first insulating film in whose surface the wiring is formed to a plasma containing a rare gas so as to form a densified layer on the surface of the first insulating film;   removing an oxide film formed on the wiring, after the densified layer is formed; and   forming a second insulating film on the wiring from which the oxide film is removed and on the densified layer, wherein:   the processes from the removal of the oxide film to the formation of the second insulating film are carried out without being atmospherically-exposed.   
     
     
         2 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the rare gas includes at least one element selected from the group consisting of He, Ar, Ne and Xe. 
     
     
         3 . The method of manufacturing a semiconductor device according to  claim 1 , wherein a protective film including at least one film selected from the group consisting of SiN film, SiCN film, SiC film and BN film is formed on an inner wall of a processing chamber before the process of exposing the first insulating film to the plasma. 
     
     
         4 . The method of manufacturing a semiconductor device according to  claim 3 , wherein the densified layer is formed by that the surface of the first insulating film is densified by that a ions generated by the plasma collide with the surface of the first insulating film and simultaneously the protective film of the inner wall is sputtered by the plasma so that the sputtered the protective film adheres to the surface of the first insulating film. 
     
     
         5 . The method of manufacturing a semiconductor device according to  claim 4 , wherein the second insulating film is formed by that a second plasma is generated in the processing chamber under conditions equal to the conditions used for forming the protective film on the inner wall. 
     
     
         6 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the oxide film is removed by exposing the wiring to a gas containing at least one gas selected from the group consisting of NH 3 , H 2  and CO that are activated by a third plasma or heating. 
     
     
         7 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the first insulating film is formed of a SiOC film. 
     
     
         8 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the processes from the formation of the densified layer to the formation of the second insulating film are carried out without being atmospherically-exposed. 
     
     
         9 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the wiring is a Cu wiring. 
     
     
         10 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the oxide film is removed by carrying out a not-activated reducing gas flow process. 
     
     
         11 . A method of manufacturing a semiconductor device, comprising:
 forming a wiring in a surface of a first insulating film on a semiconductor substrate;   exposing the first insulating film in whose surface the wiring is formed to a plasma containing a mixed gas of a rare gas and N 2  gas so as to form a densified layer on the surface of the first insulating film;   removing an oxide film formed on the wiring, after the densified layer is formed; and   forming a second insulating film on the wiring from which the oxide film is removed and the densified layer, wherein:   the processes from the removal of the oxide film to the formation of the second insulating film are carried out without being atmospherically-exposed.   
     
     
         12 . The method of manufacturing a semiconductor device according to  claim 11 , wherein the rare gas includes at least one element selected from the group consisting of He, Ar, Ne and Xe. 
     
     
         13 . The method of manufacturing a semiconductor device according to  claim 11 , wherein a protective film including at least one film selected from the group consisting of SiN film, SiCN film, SiC film and BN film is formed on an inner wall of a processing chamber before the process of exposing the first insulating film to the plasma. 
     
     
         14 . The method of manufacturing a semiconductor device according to  claim 13 , wherein the densified layer is formed by that the surface of the first insulating film is densified by that a ions generated by the plasma collide with the surface of the first insulating film and simultaneously the protective film of the inner wall is sputtered by the plasma so that the sputtered the protective film adheres to the surface of the first insulating film. 
     
     
         15 . The method of manufacturing a semiconductor device according to  claim 14 , wherein the second insulating film is formed by that a second plasma is generated in the processing chamber under conditions equal to the conditions used for forming the protective film on the inner wall. 
     
     
         16 . The method of manufacturing a semiconductor device according to  claim 11 , wherein the oxide film is removed by exposing the wiring to a gas containing at least one gas selected from the group consisting of NH 3 , H 2  and CO that are activated by a third plasma or heating. 
     
     
         17 . The method of manufacturing a semiconductor device according to  claim 11 , wherein the first insulating film is formed of a SiOC film. 
     
     
         18 . The method of manufacturing a semiconductor device according to  claim 11 , wherein the processes from the formation of the densified layer to the formation of the second insulating film are carried out without being atmospherically-exposed. 
     
     
         19 . The method of manufacturing a semiconductor device according to  claim 11 , wherein the wiring is a Cu wiring. 
     
     
         20 . The method of manufacturing a semiconductor device according to  claim 13 , wherein the oxide film is removed by carrying out a not-activated reducing gas flow process.