MULTI-STEP ANNEAL OF THIN FILMS FOR FILM DENSIFICATION AND IMPROVED GAP-FILL

• US 20070212847A1
• Filed: 04/05/2007
• Published: 09/13/2007
• Est. Priority Date: 08/04/2004
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ingle, Nitin, Yuan, Zheng, Banthia, Vikash, Pan, Rong, Xia, Xinyun, Forstner, Hali
• Application Number:
  US11/697,105
• Publication Number:
  US 20070212847A1
• Time in Patent Office: Days
• US Class Current: 438/407
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/67115 mainly by radiation
• 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

A method of annealing a substrate that has a trench containing a dielectric material formed on a silicon nitride layer between the dielectric material and the substrate, where the method includes annealing the substrate at a first temperature of about 800° C. or more in a first atmosphere comprising an oxygen containing gas, and annealing the substrate at a second temperature of about 800° C. to about 1400° C. in a second atmosphere lacking oxygen.

Claims

1. A method of annealing a substrate comprising a trench containing a dielectric material, the method comprising:

annealing the substrate at a first temperature of about 800°

C. or more in a first atmosphere comprising an oxygen containing gas; and

annealing the substrate at a second temperature of about 800°

C. to about 1400°

C. in a second atmosphere lacking oxygen,

wherein a silicon nitride layer is positioned underneath the dielectric material in the trench.

2. The method of claim 1, wherein the oxygen containing gas comprises steam (H₂O), nitric oxide (NO), or nitrous oxide (N₂O).

3. The method of claim 1, wherein the oxygen containing gas comprises in-situ generated steam (ISSG) produced from a combustion reaction of hydrogen (H₂) and oxygen (O₂) gas.

4. The method of claim 1, wherein the first atmosphere comprises nitrogen (N₂), hydrogen (H₂), ammonia (NH₃), helium (He), neon (Ne), Argon (Ar), krypton (Kr), or xenon (Xe).

5. The method of claim 1, wherein the second atmosphere comprises nitrogen (N₂), hydrogen (H₂), ammonia (NH₃), helium (He), neon (Ne), Argon (Ar), krypton (Kr), or xenon (Xe).

6. The method of claim 1, wherein the substrate is kept at the first temperature for about 30 minutes.

7. The method of claim 1, wherein the substrate is kept at the second temperature for about 30 minutes.

8. The method of claim 1, wherein the first temperature is about 900°

C.

9. The method of claim 1, wherein the second temperature is about 900°

C.

10. The method of claim 1, wherein, prior to the annealing, a wet etch rate ratio of the dielectric material to thermal oxide is about 10:

1 or more.

11. The method of claim 1, wherein, after the annealing at the second temperature, a wet etch rate ratio of the dielectric material to thermal oxide is about 1.2:

1 or less.

12. The method of claim 1, wherein the dielectric material comprises silicon dioxide.

13. The method of claim 1, wherein the substrate comprises silicon.

14. The method of claim 1, wherein the trench has an aspect ratio of about 7:

1 or more.

15. The method of claim 1, wherein the trench has a taper angle of about 87°

or more.

16. The method of claim 15, wherein the trench has a bottom and sidewalls that form and angle of about 90°

.

17. The method of claim 1, wherein the dielectric material in the trench is deposited using a chemical vapor deposition or a spin-on-dielectric technique.

18. A method of annealing a substrate comprising a trench containing a dielectric material, the method comprising:

annealing the substrate in a first stage at about 800°

C. to about 1000°

C. in the presence of water vapor; and

annealing the substrate in a second stage at a temperature from about 800°

C. to about 1100°

C. in an atmosphere that lacks the water vapor,

wherein a silicon nitride layer is positioned underneath the dielectric material in the trench.

19. The method of claim 18, wherein the water vapor is generated by in-situ generated steam (ISSG) produced from a combustion reaction of hydrogen (H₂) and oxygen (O₂) gas.

20. The method of claim 18, wherein the atmosphere that lacks water vapor comprises nitrogen (N₂).

21. The method of claim 18, wherein the first and second stage temperature is about 900°

C.

22. The method of claim 18, wherein the first stage has a duration of about 30 minutes.

23. The method of claim 18, wherein the second stage has a duration of about 30 minutes.

24. The method of claim 18, wherein the dielectric material comprises silicon oxide.

25. The method of claim 18, wherein the substrate comprises silicon.

26. A method of depositing a dielectric material on a substrate, the method comprising:

providing a trench in the substrate;

forming a barrier layer in the trench before depositing the dielectric material on the substrate;

annealing the dielectric material at a first temperature of about 800°

C. or more in a first atmosphere comprising water vapor; and

annealing the dielectric material at a second temperature of about 800°

C. to about 1400°

C. in a second atmosphere lacking water vapor.

27. The method of claim 26, wherein the barrier layer comprises silicon nitride and the dielectric material comprises silicon oxide.

28. The method of claim 26, wherein the first and second temperature is 900°

C.