Method of manufacturing a semiconductor device
Aimed at improving adhesiveness between upper and lower interconnects in semiconductor devices, a semiconductor device of the present invention includes a second dielectric multi-layered film formed on a substrate, and containing a lower interconnect; a first dielectric multi-layered film formed on the second dielectric multi-layered film, and having a recess; an MOx film formed on the inner wall of the recess, and containing a metal M and oxygen as major components; an M film formed on the MOx film, and containing the M as a major component; and an electric conductor formed on the M film so as to fill the recess, and containing Cu as a major component, wherein the surficial portion of the interconnect fallen straight under the bottom of the recess has an oxygen concentration of 1% or smaller.
1. A method of manufacturing a semiconductor device, comprising:
forming a second dielectric multi-layered film containing an interconnect on a substrate, and forming a first dielectric multi-layered film on said second dielectric multi-layered film;
forming a recess in said first dielectric multi-layered film so as to extend therethrough;
forming an MOx film, containing a metal M and oxygen as major components on said first dielectric multi-layered film and inside said recess, by a reactive film-forming process in an oxidative atmosphere;
removing a portion of said MOx film formed at the bottom of said recess;
forming an M film containing said M as a major component on said MOx film extended over the inside and the outside of said recess, and at the bottom of said recess;
forming an electric conductor containing Cu as a major component on said M film extended over the inside and the outside of said recess, so as to fill said recess; and
removing portions of said MOx film, said M film and said electric conductor laid outside of said recess.
2. The method of manufacturing a semiconductor device as claimed in claim 1 , further comprising:
forming, after said forming said recess, and before said forming said MOx film, a dielectric film containing substantially no oxygen on said first dielectric multi-layered film and inside said recess; and
removing, after said forming said dielectric film, a portion of said dielectric film formed at the bottom of said recess.
3. The method of manufacturing a semiconductor device as claimed in claim 1 , further comprising:
removing a portion of said M film formed at the bottom of said recess.
4. The method of manufacturing a semiconductor device as claimed in claim 1 ,
wherein said MOx film is formed at a film-forming temperature of −50° C. or higher and 150° C. or lower.
5. The method of manufacturing a semiconductor device as claimed in claim 1 , further comprising:
carrying out a reductive treatment of a portion of said interconnect fallen straight under the bottom of said recess, by adjusting the atmosphere to a reductive one.
6. The method of manufacturing a semiconductor device as claimed in claim 5 ,
wherein said carrying out a reductive treatment by adjusting the atmosphere to a reductive one follows said reducing the MOx film, and precedes said forming the M film.
7. The method of manufacturing a semiconductor device as claimed in claim 5 ,
wherein the reductive treatment is carried out by adjusting the atmosphere in said forming the M film to a reductive one.
8. The method of manufacturing a semiconductor device as claimed in claim 5 ,
wherein said reductive atmosphere contains at least one gas selected from H 2 , SiH 4 and NH 3 .
9. The method of manufacturing a semiconductor device as claimed in claim 1 ,
wherein said oxidative atmosphere contains at least one gas selected from O 2 , O 3 , H 2 O, organic substances containing —OH group(s), and N 2 O.
10. The method of manufacturing a semiconductor device as claimed in claim 4 ,
wherein said removing a portion of said MOx film and said forming said M film are successively carried out while keeping the atmosphere in vacuo.
11. The method of manufacturing a semiconductor device as claimed in claim 1 ,
wherein said M is Ru.