Method and apparatus for deposition of low-k films

• US 10,453,678 B2
• Filed: 04/12/2018
• Issued: 10/22/2019
• Est. Priority Date: 04/13/2017
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Li, Ning, Sun, Zhelin, Balseanu, Mihaela, Xia, Li-Qun, Bhuyan, Bhaskar Jyoti, Saly, Mark
• Primary Examiner(s): Tran, Thien F
• Application Number:
  US15/951,655
• Publication Number:
  US 20180301333A1
• Time in Patent Office: 558 Days
• Field of Search: None
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/36 Carbonitrides
• CPC Class Codes: C23C 16/45551 for relative movement of the substrate and the gas injectors or half-reaction reactor compartments
• 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 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• 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 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02326 into a nitride layer, e.g. changing SiN to SiON
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour

Abstract

Methods and apparatus for forming a conformal SiOC film on a surface are described. A SiCN film is formed on a substrate surface and exposed to a steam annealing process to decrease the nitrogen content, increase the oxygen content and leave the carbon content about the same. The annealed film has one or more of the wet etch rate or dielectric constant of the film.

Claims

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

providing a substrate having a substrate surface with a plurality of features formed therein, each feature extending a distance from the substrate surface and having a bottom and at least one sidewall;

forming a conformal film on the substrate surface; and

exposing the conformal film to a steam anneal to form an annealed conformal film with an increased oxygen content.

2. The method of claim 1, wherein the conformal film formed comprises SiCN having an initial carbon content, an initial nitrogen content and an initial oxygen content.

3. The method of claim 2, wherein the steam anneal reduces the initial nitrogen content to an annealed nitrogen content and increases the initial oxygen content to an annealed oxygen content.

4. The method of claim 3, wherein the annealed nitrogen content is less than or equal to about 1% on an atomic basis.

5. The method of claim 3, wherein an annealed carbon content after the steam anneal is within ±

10% of the initial carbon content.

6. The method of claim 5, wherein the anneal carbon content is about 10% on an atomic basis.

7. The method of claim 1, wherein the conformal film has a thickness in the range of about 10 Å

to about 500 Å

.

8. The method of claim 7, wherein the annealed conformal film has a substantially uniform composition of carbon, nitrogen and oxygen.

9. The method of claim 8, wherein the annealed conformal film has a thickness in the range of about 100 Å

to about 140 Å

.

10. The method of claim 9, wherein the annealed conformal film has a wet etch rate in dilute HF less than about 20 Å

/min for the first minute.

11. The method of claim 9, wherein the annealed conformal film has a leakage current less than or equal to about 1.5×

10<sup>−

7</sup> A/cm².

12. The method of claim 9, wherein the annealed conformal film has a dielectric constant less than 5.

13. The method of claim 1, wherein forming the conformal film comprises sequentially exposing the substrate to a silicon precursor and a reactant.

14. The method of claim 13, wherein the silicon precursor comprises bis(trichlorosilyl)methane and the reactant comprises ammonia.

15. The method of claim 1, wherein forming the conformal film and the steam anneal occur in the same processing chamber.

16. The method of claim 1, wherein forming the conformal film occurs in an atomic layer deposition chamber and the steam anneal occur in a furnace.

17. The method of claim 1, wherein the steam anneal occurs at a temperature in the range of about 300°

C. to about 600°

C.

18. The method of claim 17, wherein the steam anneal occurs with a partial pressure of water greater than or equal to about 500 Torr.

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

providing a substrate having a substrate surface with a plurality of features formed therein, each feature extending a distance from the substrate surface and having a bottom and at least one sidewall;

forming a conformal film on the substrate surface in an atomic layer deposition chamber by sequentially exposing the substrate to a silicon precursor comprising bis(trichlorosilyl)methane and a reactant comprising ammonia, the conformal film having an initial carbon content, an initial oxygen content and an initial nitrogen content;

moving the substrate from the atomic layer deposition chamber to an annealing chamber; and

exposing the conformal film to a steam anneal at a temperature in the range of about 300°

C. to about 500°

C. and a partial pressure of water of about 585 Torr to form an annealed conformal film with a thickness in the range of about 100 Å

to about 140 Å

, the annealed conformal film having an annealed carbon content, an annealed oxygen content and an annealed nitrogen content, the annealed nitrogen content lower than the initial nitrogen content, the annealed oxygen content greater than the initial oxygen content and the annealed carbon content within ±

10% of the initial carbon content, the annealed conformal film having a wet etch rate in dilute HF less than about 20 Å

/min for the first minute, a leakage current less than or equal to about 1.5×

10<sup>−

7</sup> A/cm², and a dielectric constant less than 5.