CVD flowable gap fill

• US 7,915,139 B1
• Filed: 07/23/2009
• Issued: 03/29/2011
• Est. Priority Date: 12/29/2005
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (LAM Research Corporation)
• Original Assignee: Novellus Systems Incorporated (LAM Research Corporation)
• Inventors: Lang, Chi-I, Huang, Judy H., Shanker, Sunil, Barnes, Michael
• Primary Examiner(s): LEBENTRITT, MICHAEL
• Application Number:
  US12/508,461
• Time in Patent Office: 614 Days
• Field of Search: 438/436, 438761-793, 257/E21.001, 257/4, 257/212, 257/381, 257/414, 257585-613
• US Class Current: 438/436
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02216 the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane
• 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 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76837 Filling up the space between adjacent conductive structures; Gap-filling properties of dielectrics

Abstract

The present invention meets these needs by providing improved methods of filling gaps. In certain embodiments, the methods involve placing a substrate into a reaction chamber and introducing a vapor phase silicon-containing compound and oxidant into the chamber. Reactor conditions are controlled so that the silicon-containing compound and the oxidant are made to react and condense onto the substrate. The chemical reaction causes the formation of a flowable film, in some instances containing Si—OH, Si—H and Si—O bonds. The flowable film fills gaps on the substrates. The flowable film is then converted into a silicon oxide film, for example by plasma or thermal annealing. The methods of this invention may be used to fill high aspect ratio gaps, including gaps having aspect ratios ranging from 3:1 to 10:1.

Claims

1. A method of depositing a dielectric film on a substrate surface in a reaction chamber, comprising:

a) introducing a process gas comprising a silicon-containing compound, an oxidant, and an alcohol into the reaction chamber, and

b) exposing the substrate surface to the process gas under conditions such that the oxidant reacts with the silicon-containing compound to form a flowable film on the substrate surface.

2. The method of claim 1 wherein the oxidant is selected from ozone, hydrogen peroxide and water.

3. The method of claim 1, wherein the oxidant is selected from ozone and water.

4. The method of claim 1, wherein the substrate temperature during (b) is between about −

20 and 100°

C.

5. The method of claim 4, wherein the substrate temperature during (b) is between about −

20°

C. and 35°

C.

6. The method of claim 1, wherein the silicon-containing compound is an organo-silane or an organo-siloxane.

7. The method of claim 1 wherein the silicon-containing compound is selected from TMCTS, OMCTS, TEOS, TES, TMS, MTEOS, TMOS, MTMOS, DMDMOS, Diethoxy silane (DES), triphenylethoxysilane, 1-(triethoxysilyl)-2-(diethoxymethylsilyl)ethane, tri-t-butoxylsilanol and tetramethoxy silane.

8. The method of claim 1, wherein the flowable film wholly or partially fills a gap on the substrate.

9. The method of claim 8, wherein the gap has an aspect ratio of at least about 10:

1.

10. The method of claim 1, wherein (b) takes place under non-plasma conditions.

11. The method of claim 1, wherein (b) takes place under plasma conditions.

12. The method of claim 1, wherein flowable film is formed by a single step reaction mechanism.

13. The method of claim 1, further comprising (c) densifying the flowable film.

14. The method of claim 13, wherein (c) comprises exposing the flowable film to a plasma.

15. The method of claim 13, wherein (c) comprises exposing the flowable film to an oxygen-containing plasma.

16. The method of claim 13, wherein (c) comprises the exposing the flowable film to oxygen radicals.

17. The method of claim 13, wherein (c) comprises thermally annealing the film.

18. The method of claim 1, wherein the flowable film comprises Si—

O, Si—

OH and Si—

H bonds.

19. The method of claim 1 wherein (b) comprises exposing the substrate to an oxidizing plasma.

20. A method of depositing a dielectric film on a substrate in a reaction chamber, comprising:

a) introducing a process gas comprising a silicon-containing compound and an oxidant into the reaction chamber, and

b) exposing the substrate to the process gas under conditions such that the silicon-containing compound and the oxidant react to form a flowable film on the substrate, wherein the process conditions substantially prevent the incorporation of organic groups into the flowable film.

21. The method of claim 20, further comprising (c) densifying the flowable film.

22. The method of claim 20, wherein the flowable film wholly or partially fills a gap on the substrate.

23. The method of claim 20 wherein said oxidant is selected from ozone, water and hydrogen peroxide.

24. The method of claim 20 wherein (b) comprises exposing the substrate to an oxidizing plasma.

25. The method of claim 20 further comprising exposing the flowable film to oxygen radicals.