Semiconductor device having fluorined insulating film and reduced fluorine at interconnection interfaces and method of manufacturing the same

• US 6,433,432 B2
• Filed: 01/04/2001
• Issued: 08/13/2002
• Est. Priority Date: 07/31/2000
• Status: Expired due to Term

• Current Assignee: Trinity Semiconductor Research G.k.
• Original Assignee: Fujitsu Limited
• Inventors: Shimizu, Masayuki
• Primary Examiner(s): Ho, Hoai V.
• Assistant Examiner(s): HO, TU TU V
• Application Number:
  US09/753,669
• Publication Number:
  US 20020011671A1
• Time in Patent Office: 586 Days
• Field of Search: 257/758, 257/751, 438/787, 438/622
• US Class Current: 257/758
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31629 Deposition of halogen doped silicon oxide, e.g. fluorine doped silicon oxide
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: H01L 21/76801 characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76808 involving intermediate temporary filling with material
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

There is provided a semiconductor device which comprises a trench formed in the first insulating film, a metal wiring buried in the trench and having a fluorine concentration on a surface which is lower than an oxygen concentration, a fluorine-noncontaining insulating film formed on the metal wiring, a second fluorine-containing insulating film formed on the metal wiring, holes formed at least in a lower portion of the second fluorine-containing insulating film and the fluorine-noncontaining insulating film on the first metal wiring, and metal plugs buried in the holes.

Claims

1. A semiconductor device comprising:

a semiconductor substrate;

a first insulating film formed over the semiconductor substrate and containing fluorine;

a trench formed in the first insulating film;

a first metal wiring buried in the trench and having a fluorine concentration on an upper surface which is lower than an oxygen concentration, where the upper surface of the first metal wiring being substantially the same level as an upper surface of the first insulating film;

a fluorine-noncontaining insulating film formed on the first metal wiring;

a second insulating film formed on the fluorine-noncontaining insulating film;

a hole formed at least in a lower portion of the second insulating film and the fluorine-noncontaining insulating film on the first metal wiring; and

a metal plug buried in the hole.

2. A semiconductor device according to claim 1, further comprising:

one of a second metal wiring and a metal pad buried at least in an upper portion of the second insulating film and connected to the first metal wiring via the metal plug.

3. A semiconductor device according to claim 1, wherein the fluorine concentration on the surface of the first metal wiring is less than 3.9 atom %.

4. A semiconductor device according to claim 1, wherein the first metal wiring has a plural-layered structure consisting of an underlying metal film and a main metal film.

5. A semiconductor device according to claim 4, wherein the main metal film is formed of a copper film.

6. A semiconductor device according to claim 1, wherein the fluorine-noncontaining insulating film is formed of a silicon nitride film or a silicon carbide film.

7. A semiconductor device comprising:

a semiconductor substrate;

a first insulating film formed over the semiconductor substrate and containing fluorine;

a trench formed in the first insulating film;

a first metal wiring buried in the trench and having a fluorine concentration on an upper surface which is less than 10 atom % where the upper surface of the first metal wiring being substantially the same level as an upper surface of the first insulating film;

a fluorine-noncontaining insulating film formed on the first metal wiring;

a second insulating film formed on the fluorine-noncontaining insulating film;

a hole formed at least in a lower portion of the second insulating film and on the first metal wiring in the fluorine-noncontaining insulating film; and

a metal plug buried in the hole.

8. A semiconductor device according to claim 7, further comprising:

one of a second metal wiring and a metal pad buried at least in an upper portion of the second insulating film and connected to the first metal wiring via the metal plug.

9. A semiconductor device according to claim 7, wherein the fluorine concentration on the surface of the first metal wiring is less than 3.9 atom %.

10. A semiconductor device according to claim 7, wherein the first metal wiring has a plural-layered structure consisting of an underlying metal film and a main metal film.

11. A semiconductor device according to claim 10, wherein the main metal film is formed of a copper film.

12. A semiconductor device according to claim 7, wherein the fluorine-noncontaining insulating film is formed of a silicon nitride film or a silicon carbide film.

13. A semiconductor device manufacturing method comprising the steps of:

forming a first fluorine-containing insulating film over a semiconductor substrate;

forming a trench in the first fluorine-containing insulating film;

forming a first metal film in the trench and on the first fluorine-containing insulating film;

leaving the first metal film in the trench and removing the first metal film from an upper surface of the first fluorine-containing insulating film, by polishing the first metal film;

reducing an amount of fluorine adhered to a polished surface of the first metal film being left in the trench; and

forming a fluorine-noncontaining insulating film on the first metal film in the trench and the first fluorine-containing insulating film.

14. A semiconductor device manufacturing method according to claim 13, wherein the step of reducing the amount of fluorine adhered to the surface of the first metal film being left in the trench, including the steps of,

sputtering a surface of the first metal film in the trench, and

exposing the surface to a reducing gas plasma.

15. A semiconductor device manufacturing method according to claim 13, wherein the step of reducing the amount of fluorine adhered to the surface of the first metal film being left in the trench, is the step of re-polishing by changing conditions after the metal film is removed from an upper surface of the first fluorine-containing insulating film by polishing.

16. A semiconductor device manufacturing method according to claim 13, wherein the first metal wiring is formed as a plural-layered structure consisting of an underlying metal film and an overlying main metal film.

17. A semiconductor device manufacturing method according to claim 16, further comprising the step of:

removing the underlying metal film from an upper surface of the first fluorine-containing insulating film by polishing the underlying metal film while changing conditions after the main metal film is left in the trench by polishing.

18. A semiconductor device manufacturing method according to claim 16, wherein the main metal film is formed of a copper film, and the underlying metal film is formed of a metal nitride film.

19. A semiconductor device manufacturing method according to claim 13, wherein, after an amount of the fluorine that is adhered onto the surface of the first metal film in the trench is reduced, an amount of the fluorine on the surface is set lower than an oxygen concentration on the surface of the first metal film.

20. A semiconductor device manufacturing method according to claim 13, wherein, after an amount of the fluorine that is adhered onto the surface of the first metal film in the trench is reduced, an amount of the fluorine on the surface is less than 3.9 atom %.

21. A semiconductor device manufacturing method according to claim 13, further comprising the steps of:

forming a second fluorine-containing insulating film on the fluorine-noncontaining insulating film;

forming a hole in the second fluorine-containing insulating film and the fluorine-noncontaining insulating film over the first metal wiring; and

forming a metal plug in the hole.

22. A semiconductor device manufacturing method according to claim 21, further comprising the steps of:

forming an upper trench, that is connected to the metal plug, in an upper portion of the second fluorine-containing insulating film; and

forming one of a metal wiring and a metal pad to be buried in the upper trench.

23. A semiconductor device manufacturing method according to claim 22, wherein the metal wiring or the metal pad and the metal plug are formed by burying simultaneously a second metal film in the holes and the upper trench, and then removing the second metal film from an upper surface of the second fluorine-containing insulating film by polishing the second metal film.