Method of plasma enhanced chemical vapor deposition of phosphosilicate glass film

• US 4,394,401 A
• Filed: 08/07/1981
• Issued: 07/19/1983
• Est. Priority Date: 08/08/1980
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Takagi, Mikio, Shioya, Yoshimi, Maeda, Mamoru, Takasaki, Kanetake
• Primary Examiner(s): Smith, John D.
• Application Number:
  US06/290,978
• Time in Patent Office: 711 Days
• Field of Search: 427/39, 427/45.1, 427/85, 427/95
• US Class Current: 427/574
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• 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 21/02129 the material being boron or phosphorus doped silicon oxides, e.g. BPSG, BSG or PSG
• 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 21/31625 Deposition of boron or phosphorus doped silicon oxide, e.g. BSG, PSG, BPSG

Abstract

A method of plasma enhanced chemical vapor deposition of a phosphosilicate glass film on a substrate from a reaction gas mixture including SiH₄, N₂ O and PH₃ is disclosed. This deposition is effected under the conditions such that a mol ratio of N₂ O to SiH₄ (N₂ O/SiH₄) in the reaction gas mixture is 50 or more and that a mol ratio of PH₃ to SiH₄ (PH₃ /SiH₄) in the reaction gas mixture is 0.08 or less. In the phosphosilicate glass film thus deposited, no cracking occurs due to a high temperature heat-treatment and due to the stress, caused by cooling the deposited films to an ordinarily ambient temperature.

Claims

1. A method of plasma enhanced chemical vapor deposition of a phosphosilicate glass film on a substrate comprising the step of exposing the substrate to a reaction gas mixture including SiH₄, N₂ O and PH₃, said deposition being effected under conditions such that the reaction gas mixture has a mol ratio of N₂ O to SiH₄ (N₂ O/SiH₄) which is greater than or equal to 50 and a mol ratio of PH₃ to SiH₄ (PH₃ /SiH₄) which is less than or equal to 0.08.

2. A method as claimed in claim 1, wherein the exposing step is effected at a pressure of from 0.1 to 2 Torr and at a temperature of from 20°

to 450°

C.

3. A method as claimed in claim 1, wherein the exposing step is effected by using a radio-frequency power of from 50 KHz to 2.45 GHz.

4. A method as claimed in claim 1, wherein the mol ratio of N₂ O to SiH₄ in the reaction gas mixture is from 50 to 100.

5. A method as claimed in claim 1, wherein the mol ratio of PH₃ to SiH₄ in the reaction gas mixture is from 0.03 to 0.06.

6. A method of depositing a phosphosilicate glass film on a substrate, comprising the steps of:

(a) placing the substrate within a chamber;

(b) evacuating the chamber;

(c) heating the atmosphere in the chamber;

(d) introducing a reaction gas mixture of SiH₄, N₂ O, and PH₃ into the chamber, the mol ratio of N₂ O to SiH₄ being greater than or equal to 50 and the mol ratio of PH₃ to SiH₄ being less than or equal to 0.08; and

(e) applying radio-frequency power to the reaction gas mixture so that the phosphosilicate glass film is deposited on the substrate.

7. A method as claimed in claim 6, wherein said evacuating step (b) includes maintaining the atmosphere in the chamber at a pressure of from 0.1 to 2 Torr.

8. A method as claimed in claim 7, wherein the step (e) includes applying a radio-frequency power of from 50 KHz to 2.45 GHz.

9. A method as claimed in claim 8, wherein said heating step (c) comprises heating the atmosphere to a temperature of from 20°

to 450°

C.

10. A method as claimed in claim 9, wherein the mol ratio of N₂ O to SiH₄ in the reaction gas mixture is from 50 to 100 and wherein the mol ratio of PH₃ to SiH₄ in the reaction gas mixture is from 0.03 to 0.06.