Process for plasma depositing silicon nitride and silicon dioxide films onto a substrate

• US 4,877,641 A
• Filed: 05/31/1988
• Issued: 10/31/1989
• Est. Priority Date: 05/31/1988
• Status: Expired due to Fees

• Current Assignee: OLIN Corporation
• Original Assignee: OLIN Corporation
• Inventors: Dory, Thomas S.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/200,202
• Time in Patent Office: 518 Days
• Field of Search: 427/38, 427/45.1, 427/255, 427/255.2, 427/255.3, 437/238, 437/241, 437/243
• US Class Current: 427/574
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/402 Silicon dioxide

Abstract

A plasma CVD process for forming silicon nitride-type or silicon dioxide-type films onto a substrate comprising the steps of:

(a) introducing di-tert-butylsilane and at least one other reactant gas into a CVD reaction zone containing said substrate on which either a silicon nitride-type or silicon dioxide-type film is to be formed;

(b) maintaining the temperature of said zone and said substrate from about 100° C. to about 350° C.;

(c) maintaining the pressure in said zone from about 0.1 to about 5 Torr; and

(d) passing said gas mixture into contact with said substrate while exciting said gas mixture with a plasma for a period of time sufficient to form a silicon nitride-type or silicon dioxide-type film on said substrate, wherein said plasma is excited by a RF power at about 10 to 500 Watts.

Claims

1. A plasma CVD process for forming silicon nitride film having a refractive index from about 2.0±

0.2 or silicon dioxide film having a refractive index from about 1.46±

0.2 a substrate comprising the steps of;

(a) introducing di-tert-butylsilane and at least one other reactant gas capable of reacting with said di-tert-butylsilane to form either silicon nitride or silicon dioxide into a CVD reaction zone containing said substrate on which either a silicon nitride or silicon dioxide film is to be formed;

(b) maintaining the temperature of said zone and said substrate from about 100°

C. to about 350°

C.;

(c) maintaining the pressure in said zone from about 0.1 to about 5 Torr; and

(d) passing said gas mixture into contact with said substrate while exciting said gas mixture with a plasma for a period of time sufficient to form a silicon from about 2.0 ±

0.2 or silicon dioxide film having a refractive index from about 1.46 ±

0.2 on said nitride film having a refractive index substrate, wherein said plasma is excited by a RF power at about 10 to 500 Watts.

2. The plasma CVD process of claim 1 wherein a silicon nitride film is formed and said other gas is anhydrous ammonia.

3. The plasma CVD process of claim 2 wherein the plasma is formed at 50 KHz frequency and at a power of about 100 to about 500 Watts.

4. The plasma CVD process of claim 3 wherein the flow rate of said di-tert-butylsilane into said zone is from about 50 sccm to about 300 sccm and the flow rate into said zone of said anhydrous ammonia is from about 1000 sccm to about 3000 sccm.

5. The plasma CVD process of claim 1 wherein a silicon nitride film is formed and said other gases are a mixture of nitrogen and anhydrous ammonia.

6. The plasma CVD process of claim 5 wherein the plasma is formed at 13.56 MHz frequency at about 10 to about 100 Watts.

7. The plasma CVD process of claim 6 wherein the flow rate of said di-tert-butylsilane into said zone is from about 50 sccm to about 300 sccm, the flow rate of said nitrogen into said zone is from about 200 sccm to about 700 sccm, and the flow rate of said anhydrous ammonia into said zone is from about 2 sccm to about 20 sccm.

8. The plasma CVD process of claim 1 wherein said zone temperature and said substrate temperature are from about 125°

C. to about 325°

C.

9. The plasma CVD process of claim 1 wherein silicon dioxide film is formed and said other gas is nitrous oxide or a mixture of nitrous oxide and nitric oxide, wherein the flow rate of said di-tert-butylsilane is from about 50 sccm to about 300 sccm, the flow rate of nitrous oxide into said zone is from about 200 sccm to about 4000 sccm and the flow rate of nitric oxide is from 0 to about 4000 sccm.

10. The plasma CVD process of claim 9 wherein said plasma is formed at 50 KHz at about 100 to about 500 Watts.

11. The plasma CVD process of claim 9 wherein the plasma is formed at 13.56 MHz at about 10 to about 100 Watts.

12. The plasma CVD process of claim 1 wherein said zone pressure is from about 0.2 Torr. to about 4 Torr.

13. The plasma CVD process of claim 1 wherein said film formation rate is maintained at a rate from about 10 to about 500 Angstroms/minute.

22. The plasma CVD process of claim 1 wherein said substrate is selected from the group consisting of resin objects or films, glass objects or films, metal objects or films, and semiconductor layers or devices.

14. A plasma CVD process for forming silicon nitride film having a refractive index from about 2.0±

0.2 onto a substrate comprising the steps of;

(a) introducing di-tert-butylsilane and at least one other reactant gas capable of reacting with said di-tert-butylsilane to form silicon nitride into a CVD reaction zone containing said substrate on which said silicon nitride film is to be formed;

(b) maintaining the temperature of said zone and said substrate from about 125°

C. to about 325°

C.;

(c) maintaining the pressure in said zone in the range from about 0.2 to about 4 Torr.; and

(d) maintaining said gas mixture into contact with said substrate while exciting said gas mixture with a plasma for a period of time sufficient to form a silicon nitride film thereon having a refractive index of about 2.0±

0.2, wherein said plasma is excited by a RF frequency of 50 KHz at about 100 to about 500 Watts or by a RF frequency of 13.56 MHz at about 10 to about 100 Watts.

15. The plasma CVD process of claim 14 wherein said other reactant gas is anhydrous ammonia.

16. The plasma CVD process of claim 15 wherein said plasma was struck at a frequency of 50 KHz and the flow rate of said di-tert-butylsilane into said zone is from about 75 sccm to about 200 sccm and the flow rate of said anhydrous ammonia is from about 1500 sccm to about 2500 sccm.

17. The plasma CVD process of claim 16 wherein said zone temperature and said substrate temperature are from about 200°

C. to about 300°

C. and said zone pressure is from about 1 Torr. to about 3 Torr.

23. The plasma CVD process of claim 14 wherein said substrate is selected from the group consisting of resin objects or films, glass objects or films, metal objects or films, and semiconductor layers or devices.

18. A plasma CVD process for forming silicon dioxide film having a refractive index of about 1.46 ±

0.2 onto a substrate comprising the steps of;

(a) introducing di-tert-butylsilane and at least one other reactant gas capable of reacting with said di-tert-butylsilane to form silicon dioxide into a CVD reaction zone containing said substrate on which a silicon dioxide film is to be formed;

(b) maintaining the temperature of said zone and said substrate from about 125°

C. to about 325°

C.;

(c) maintaining the presence in said zone from about about 0.2 to about 4 Torr., and

(d) passing said gases into contact with substrate while exciting said gas mixture with a plasma for a period of time sufficient to form a silicon dioxide film thereon having a refractive index of about 1.46±

0.2, wherein said plasma is excited by a RF frequency of 50 KHz at a power of about 100 to about 500 Watts or by a RF frequency of 13.56 MHz at a power of about 10 to about 100 Watts.

19. The plasma CVD process of claim 18 wherein said other reactant gas is nitrous oxide or a m of nitrous oxide and nitric oxide.

20. The plasma CVD process of claim 19 wherein the flow rate of said di-tert-butylsilane into said zone is from about 75 sccm to about 200 sccm, the flow rate of said nitrous oxide is from about 300 sccm to about 3000 sccm and the flow rate of said nitric oxide is from 0 to about 2000 sccm.

21. The plasma CVD process of claim 20 wherein said zone temperature is from about 200°

C. to about 300°

C.

24. The plasma CVD process of claim 18 wherein said substrate is selected from the group consisting of resin objects or films, glass objects or films, metal objects or films, and semiconductor layers or devices.