LOW-K OXIDE DEPOSITION BY HYDROLYSIS AND CONDENSATION

• US 20150004806A1
• Filed: 08/20/2014
• Published: 01/01/2015
• Est. Priority Date: 11/01/2006
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Antonelli, George Andrew, Ndiege, Nicholas Muga, Nittala, Krishna, Wong, Derek B., Draeger, Nerissa Sue, Van Cleemput, Patrick A.
• Granted Patent: US 9,245,739 B2
• Time in Patent Office: Days
• US Class Current: 438/789
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/56 After-treatment
• 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 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02219 the compound comprising silicon and nitrogen
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02277 the reactions being activated by other means than plasma or thermal, e.g. photo-CVD
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/02345 treatment by exposure to radiation, e.g. visible light
• CPC Class Codes: H01L 21/3105 After-treatment

Abstract

Methods for depositing flowable dielectric films using halogen-free precursors and catalysts on a substrate are provided herein. Halogen-free precursors and catalysts include self-catalyzing aminosilane compounds and halogen-free organic acids. Flowable films may be used to fill pores in existing dielectric films on substrates having exposed metallization layers. The methods involve hydrolysis and condensation reactions.

Claims

1. A method of depositing a film on a semiconductor substrate, the method comprising:

introducing process gases comprising a silicon-containing precursor, an oxidant, and a halogen-free acid catalyst compound to a reaction chamber; and

exposing the substrate to the process gases under conditions such that a condensed flowable film forms on the substrate,

wherein the chemical reactions that form the flowable film comprise a S_N1 hydrolysis mechanism and condensation.

2. The method of claim 1, wherein the halogen-free catalyst compound is selected from the group consisting of acetic acid, and photosensitive organic acid catalysts.

3. The method of claim 2, wherein the photosensitive organic acid catalyst is selected from the group consisting of sulfonic acid, picric acid, tartaric acid, citric acid, ethylenediaminetetraacetic acid, pyrophosphoric acid, substituted derivatives of these acids, and combinations thereof.

4. The method of claim 2, wherein the substrate is exposed to the process gases while the substrate is exposed to UV radiation.

5. The method of claim 1, wherein the oxidant is selected from the group consisting of water, ozone, and peroxide.

6. The method of claim 1, wherein the silicon-containing precursor and the oxidant are introduced to the reaction chamber via separate inlets.

7. The method of claim 1, wherein the halogen-free catalyst compound is introduced to the reaction chamber separate from the silicon-containing precursor and the oxidant.

8. The method of claim 1, further comprising treating the flowable film.

9. The method of claim 8, wherein treating the flowable film comprises exposing the flowable film to the oxidant and exposing the film to a thermal or plasma environment.

10. The method of claim 1, wherein the flowable film seals pores having an average critical dimension between about 1 Å

and about 1 nm.

11. A method of depositing a film on a semiconductor substrate, the method comprising:

introducing process gases comprising a silicon-containing precursor, an oxidant, and a halogen-free catalyst compound to a reaction chamber; and

exposing the substrate to the process gases under conditions such that a condensed flowable film forms on the substrate,

wherein the catalyst compound is selected from the group consisting of sulfonic acid, picric acid, tartaric acid, citric acid, ethylenediaminetetraacetic acid, pyrophosphoric acid, and combinations thereof.

12. The method of claim 11, wherein the flowable film comprises a carbon-doped silicon oxide film.

13. A method of depositing a film on a semiconductor substrate, the method comprising:

introducing process gases comprising a silicon-containing precursor and an oxidant to a reaction chamber; and

exposing the substrate to the process gases under conditions such that a condensed flowable film forms on the substrate,

wherein the silicon-containing precursor is a halogen-free self-catalyzing aminosilane compound, and

wherein the chemical reactions that form the flowable film comprise a hydrolysis mechanism between an amine group on the aminosilane compound and the oxidant, and condensation.

14. The method of claim 13, wherein the silicon-containing precursor is halogen-free.

15. The method of claim 13, further comprising treating the flowable film by exposing the flowable film to the oxidant.

16. The method of claim 13, wherein the chemical structure of the silicon-containing precursor comprises at least one N-alkylamine group.

17. The method of claim 16, wherein the chemical structure of a silicon-containing precursor further comprises at least one ligand selected from the group consisting of N-alkyl amine;

N,N dialkyl amine;

alkoxy;

alkyl;

alkenyl;

alkynyl;

aromatic groups; and

hydrogen.

18. The method of claim 13, wherein the flowable film seals pores having an average critical dimension between about 1 Å

and about 1 nm.

19. A method of depositing a film on a semiconductor substrate, the method comprising:

introducing process gases comprising a halogen-free silicon-containing precursor and an oxidant to a reaction chamber; and

exposing the substrate to the process gases under conditions such that a condensed flowable film forms on the substrate,

wherein the halogen-free silicon-containing precursor is selected from the group consisting of dimethylamino trimethylsilane, dimethylaminotriethylsilane, bisdimethylaminodiethylsilane, trisdimethylamino methylsilane, trismethylamino methylsilane, trismethylamino silane, bisdimethylamino dimethylsilane, bisdimethylamino ethoxy methyl silane, methylamino diethoxy methyl silane, trismethylamino vinyl silane, bismethylamino divinyl silane, bisdimethylamino ethoxy vinyl silane acetoxysilane, and combinations thereof.

20. The method of claim 19, further comprising treating the flowable film by exposing the flowable film to the oxidant.