Sequential deposition/anneal film densification method

• US 7,148,155 B1
• Filed: 10/26/2004
• Issued: 12/12/2006
• Est. Priority Date: 10/26/2004
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Inventors: Papasouliotis, George D., Rulkens, Ron, Hausmann, Dennis M., Nie, Bunsen, Tipton, Adrianne K., Tobin, Jeff, Tarafdar, Raihan M.
• Primary Examiner(s): Everhart, Caridad
• Application Number:
  US10/975,028
• Time in Patent Office: 777 Days
• Field of Search: 438/778, 438/775, 257/E21.576, 427/255.7, 427/255.18, 427/255.28, 427/255.393, 427/255.37
• US Class Current: 438/778
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/31612 on a silicon body
• 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 silicon dioxide-based dielectric layer is formed on a substrate surface by a sequential deposition/anneal technique. The deposited layer thickness is insufficient to prevent substantially complete penetration of annealing process agents into the layer and migration of water out of the layer. The dielectric layer is then annealed, ideally at a moderate temperature, to remove water and thereby fully densify the film. The deposition and anneal processes are then repeated until a desired dielectric film thickness is achieved.

Claims

1. A method of forming a densified dielectric film, the method comprising:

(a) depositing a thin layer of a silicon oxide-based dielectric film layer on the substrate;

(b) annealing the dielectric film layer to remove water and fully densify the layer, wherein the annealing comprises a treatment selected from the group consisting of a low temperature oxygen-containing inductively coupled high density plasma (HDP)-based treatment, a furnace-based thermal treatment, and a microwave plasma-based treatment; and

(c) repeating (a) and (b) at least once to form a densified dielectric film;

wherein the thickness of the dielectric film layer formed in (a) is insufficient to prevent substantially complete penetration of the annealing agent into the layer and migration of water out of the layer.

2. The method of claim 1, wherein the film layer thickness is between 300 and 3000 Å

.

3. The method of claim 1, wherein the film layer thickness is between 500 and 1500 Å

.

4. The method of claim 1, wherein the film layer thickness is about 1000 Å

.

5. The method of claim 1, wherein (a) comprises a thermal chemical vapor deposition of a silicon-containing precursor.

6. The method of claim 1, wherein the anneal comprises a microwave plasma-based treatment.

7. The method of claim 1, wherein the anneal comprises a laser ablation-based treatment.

8. The method of claim 1, wherein the (a) and (b) are conducted in situ in a single reactor chamber.

9. The method of claim 1, wherein the silicon-containing precursor is at least one of a silanol and a silanediol.

10. The method of claim 1, wherein (a) comprises:

(i) exposing the substrate surface to a metal catalyst-containing precursor gas to form a substantially saturated layer of metal catalyst-containing precursor on the substrate surface; and

(ii) exposing the substrate surface to a silicon-containing precursor gas to form a silicon oxide-based dielectric film layer on the substrate.

11. The method of claim 10, wherein the metal catalyst-containing precursor is selected from the list of metal catalyst-containing precursors comprising aluminum, zirconium, hafnium, gallium, titanium, niobium, and tantalum.

12. The method of claim 10, wherein the metal catalyst-containing precursor is an aluminum-containing precursor.

13. The method of claim 10, wherein the aluminum-containing precursor is at least one of hexakis(dimethylamino)aluminum and trimethyl aluminum.

14. The method of claim 1, wherein the anneal comprises a furnace-based thermal treatment.

15. The method of claim 14, wherein the anneal is conducted in an oxidizing environment.

16. The method of claim 1, wherein the (a) and (b) are conducted in separate reactor chambers.

17. The method of claim 16, wherein the separate reactor chambers are integrated in a single apparatus.

18. The method of claim 1, wherein the substrate is a partially fabricated semiconductor wafer.

19. The method of claim 18, wherein the dielectric film is deposited over gaps in the partially fabricated semiconductor wafer.

20. The method of claim 19, wherein the thickness of the film layer is less than half the trench width.

21. The method of claim 20, wherein the thickness of the dielectric film layer formed in (a) is insufficient to prevent substantially complete penetration of the annealing agent into the layer and migration of water out of the layer.

22. The method of claim 1, wherein the anneal comprises a low temperature oxygen-containing inductively coupled high density plasma (HDP)-based treatment.

23. The method of claim 22, wherein the annealing is conducted for a time period of about 10 minutes.

24. The method of claim 22, wherein the HDP anneal is conducted at a temperature of less than 500°

C. for at least 5 minutes at a source power of at least 3000 W.

25. The method of claim 24, wherein the annealing is conducted at a temperature between about 400 and 500°

C.

26. The method of claim 25, wherein the annealing is conducted at a temperature of about 400°

C.

27. The method of claim 22, wherein the oxygen in the plasma is provided by an oxygen-containing precursor gas.

28. The method of claim 27, wherein the oxygen-containing precursor gas comprises one selected from the group consisting of H₂O, air, O₂, O₃ and H₂O₂ and combinations thereof.

29. The method of claim 28, wherein the oxygen-containing gas comprises air.

30. The method of claim 29, wherein the oxygen-containing gas comprises O₂.

31. The method of claim 30, wherein the O₂ has a partial pressure of greater than 100 mTorr.

32. A method of filling a gap on a semiconductor substrate, the method comprising:

(a) partially filling the gap by depositing a thin layer of a silicon oxide-based dielectric film layer on the substrate;

(b) annealing the dielectric film layer to remove water and fully densify the layer; and

(c) repeating (a) and (b) at least once until the gap is filled with a densified dielectric film.

33. The method of claim 32, wherein (a) comprises:

(i) exposing the substrate surface to a metal catalyst-containing precursor gas to form a substantially saturated layer of metal catalyst-containing precursor on the substrate surface; and

(ii) exposing the substrate surface to a silicon-containing precursor gas to form a silicon oxide-based dielectric film layer on the substrate.

34. The method of claim 33, wherein the anneal comprises a low temperature oxygen-containing inductively coupled high density plasma (HDP)-based treatment.