NOVEL GAP FILL INTEGRATION

• US 20110151678A1
• Filed: 12/09/2010
• Published: 06/23/2011
• Est. Priority Date: 12/09/2009
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Inventors: Ashtiani, Kaihan, Wood, Michael, Nittala, Lakshminarayana, Drewery, John, Shoda, Naohiro, Draeger, Nerissa, van Schravendijk, Bart
• Granted Patent: US 8,728,958 B2
• Time in Patent Office: Days
• US Class Current: 438/786
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02208 the precursor containing a compound comprising Si
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/76224 using trench refilling with dielectric materials trench filling with polycristalline silicon H01L21/763; together with vertical isolation, e.g. trench refilling in a SOI substrate H01L21/76264

Abstract

Novel gap fill schemes involving depositing both flowable oxide films and high density plasma chemical vapor deposition oxide (HDP oxide) films are provided. According to various embodiments, the flowable oxide films may be used as a sacrificial layer and/or as a material for bottom up gap fill. In certain embodiments, the top surface of the filled gap is an HDP oxide film. The resulting filled gap may be filled only with HDP oxide film or a combination of HDP oxide and flowable oxide films. The methods provide improved top hat reduction and avoid clipping of the structures defining the gaps.

Claims

1. A method of filling an unfilled gap on a semiconductor substrate, the method comprising:

depositing a flowable dielectric film in the gap to partially fill the gap;

after partially filling the gap with the flowable dielectric film, depositing a high density plasma chemical vapor deposition (HDP-CVD) dielectric film via a high density plasma chemical vapor deposition reaction in the gap to complete fill of the gap, wherein the flowable dielectric film is uncured prior to the subsequent HDP-CVD deposition.

2. The method of claim 1 wherein the flowable dielectric film is a silicon oxide film, a silicon nitride film or a silicon oxynitride film.

3. The method of claim 1 wherein depositing a flowable dielectric film in the gap comprises introducing a process gas comprising a silicon-containing precursor, an oxidant and an optional solvent, wherein the process gas is characterized by the following partial pressure (Pp):

vapor pressure (Pvp) ratios;

silicon-containing precursor;

0.01-1;

oxidant;

0.25-2; and

solvent;

0.1-1.

4. The method of claim 1 wherein depositing a flowable dielectric film in the gap comprises introducing a process gas comprising a silicon-containing precursor, an oxidant and a solvent, wherein the process gas is characterized as having an oxidant:

precursor partial pressure ratio of about 5 to 15.

5. The method of claim 1 wherein depositing a flowable dielectric film in the gap comprises introducing a process gas comprising a silicon-containing precursor, an oxidant and a solvent, wherein the process gas is characterized as having an solvent:

oxidant precursor partial pressure ratio of about 0.1-5.

6. The method of claim 1 wherein flowable dielectric film is at least partially densified and/or oxidized during deposition of the HDP-CVD dielectric film.

13. The method of claim 1 wherein the gap is filled following a lithographic process.

7. A method of filling an unfilled gap on a semiconductor substrate, the method comprising:

providing the substrate to a deposition module;

depositing a flowable dielectric film in the gap to partially fill the gap;

oxidizing the flowable dielectric film in the gap;

transferring the substrate from the deposition module to an high density plasma chemical vapor deposition (HDP-CVD) module; and

depositing a HDP dielectric film to complete fill of the gap.

8. The method of claim 7 wherein oxidizing the flowable dielectric film is performed in the deposition module.

9. The method of claim 7 wherein oxidizing the flowable dielectric film is performed in the HDP-CVD module.

10. The method of claim 7 wherein oxidizing the flowable dielectric film is performed in a cure module separate from the deposition module.

11. The method of claim 7 wherein oxidizing the flowable dielectric film comprises one of:

exposing the film to an oxidant in the presence of ultraviolet light and exposing the film to a remotely-generated oxidizing plasma.

12. The method of claim 7 wherein oxidizing the flowable dielectric film comprises exposing the film to a direct (in situ) plasma.

14. A method of filling an unfilled gap on a semiconductor substrate, the method comprising:

depositing a flowable dielectric film in the gap to partially fill the gap;

partially densifying the flowable dielectric film in the gap; and

depositing a HDP dielectric film to complete fill of the gap.

15. The method of claim 14 wherein partially densifying the flowable dielectric film comprises exposing the film to a remote or direct plasma.

16. The method of claim 15 wherein the plasma is an oxidizing plasma.

17. The method of claim 15 wherein the plasma is an inert plasma.

18. A method of filling an unfilled gap on a substrate, the method comprising:

introducing a process gas comprising a silicon-containing precursor, an oxidant and an optional solvent to thereby deposit a flowable film in the gap to partially fill the gap, wherein the process gas is characterized by the following partial pressure (Pp);

vapor pressure (Pvp) ratios;

silicon-containing precursor;

0.01-1;

oxidant;

0.25-2; and

solvent;

0.1-1;

after partially filling the gap with the flowable oxide film, depositing a HDP dielectric film to complete fill of the gap.

19. The method of claim 18 wherein the Pp:

Pvp ratio of the silicon-containing precursor is between 0.01 and 0.5.

20. The method of claim 18 wherein the Pp:

Pvp ratio of the oxidant is between 0.5 and 1.

21. The method of claim 18 wherein the Pp:

Pvp ratio of the oxidant is between 0.1 and 1.

22. The method of claim 18 wherein the process gas is further characterized as having an oxidant:

precursor partial pressure ratio of about 5 to 15.

23. The method of claim 18 wherein the process gas is further characterized as having a solvent:

oxidant precursor partial pressure ratio of about 0.1-5.

24. An apparatus comprising:

a flowable oxide deposition chamber configured to deposit flowable oxide film;

a high density plasma chemical vapor deposition (HDP-CVD) deposition chamber configured to deposit HDP oxide film; and

a controller, said controller comprising instructions for introducing into the flowable oxide deposition chamber a process gas including a silicon-containing precursor, an oxidant and an optional solvent, wherein the process gas is characterized by the following partial pressure (Pp);

vapor pressure (Pvp) ratios;

silicon-containing precursor;

0.01-1, oxidant;

0.25-2; and

solvent;

0.1-1.