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US3887726A
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Method of chemical vapor deposition to provide silicon dioxide films with reduced surface state charge on semiconductor substrates
Assignee: International Business Machines Corp
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Filing: 1973-06-29
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Granted: 1975-06-03
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Expires: 1993-06-29
Abstract
Abstract The present invention relates to an improvement in the conventional method of forming silicon dioxide films by a chemical-vapor deposition reaction of a mixture of an oxidizing agent and SiHnCl(4 n), where n is an integer of from 0 to 4. Such conventional methods which are conducted at temperatures of at least 700*C provide silicon dioxide films on silicon substrates which are substantially free of mobile ion contamination as evidenced by insignificant flat-band voltage shift when subjected to standard bias-temperature test conditions; such insignificant flat-band voltage shifts are indicative of a maximum increase of 1 X 1011 charges/cm2 in the flat-band surface charge resulting from such bias-temperature conditions. The improved method of the present invention involves adding HCl from an external source to the conventional chemical-vapor deposition reaction mixture. The addition of the HCl provides a silicon dioxide covered silicon substrate, with reduced surface state charges.
Inventors
- 👤 Robert L Bratter
- 👤 Arun K Gaind
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:17
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/40; C23C16/401; C23C16/402; H10P14/66; H10P14/668; H10P14/6681; H10P14/6682; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6334
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
79 words
IN THE METHOD OF FORMING SILICON DIOXIDE FILMS ON SILICON SUBSTRATES BY A CHEMICAL-VAPOR DEPOSITION REACTION OF A MIXTURE OF AN OXIDIZING AGENT AND SIHNCL(4-N), WHEREIN N IS AN INTEGER OF FROM 0 TO 4, TO DEPOSIT SILICON DIOXIDE FILMS DISPLAYING A MAXIMUM INCREASE OF 1X10**11 CHARGES/CM2 IN SURFACE CHARGE WHEN SUBJECTED TO BIAS-TEMPERATURES TEST CONDITIONS OF APPLIED FIELD OF 2X10**6 V/CM FOR 30 MINUTES AT 250*C, THE IMPROVEMENT OF ADDING HCL FROM AN EXTERNAL SOURCE TO SAID REACTANTS.
Claim 2
Dependent Claim
79 words
IN THE METHOD OF FORMING SILICON DIOXIDE FILMS ON SILICON SUBSTRATES BY A CHEMICAL-VAPOR DEPOSITION REACTION OF A MIXTURE OF AN OXIDIZING AGENT AND SIHNCL(4-N), WHEREIN N IS AN INTEGER OF FROM 0 TO 4, TO DEPOSIT SILICON DIOXIDE FILMS DISPLAYING A MAXIMUM INCREASE OF 1X10**11 CHARGES/CM2 IN SURFACE CHARGE WHEN SUBJECTED TO BIAS-TEMPERATURES TEST CONDITIONS OF APPLIED FIELD OF 2X10**6 V/CM FOR 30 MINUTES AT 250*C, THE IMPROVEMENT OF ADDING HCL FROM AN EXTERNAL SOURCE TO SAID REACTANTS.
Claim 3
Dependent Claim
84 words
In the method of forming silicon dioxide films on silicon substrates by a chemical-vapor deposition reaction of a mixture of an oxidizing agent and SiHnCl(4 n), where n is an integer of from 0 to 4, to deposit silicon dioxide films displaying a maximum increase of 1 X 1011 charges/cm2 in surface charge when subjected to bias-temperature test conditions of applied field of 2 X 106 V/cm for 30 minutes at 250*C, the improvement of adding HCl from an external source to said reactants.
Claim 4
Dependent Claim
84 words
In the method of forming silicon dioxide films on silicon substrates by a chemical-vapor deposition reaction of a mixture of an oxidizing agent and SiHnCl(4 n), where n is an integer of from 0 to 4, to deposit silicon dioxide films displaying a maximum increase of 1 X 1011 charges/cm2 in surface charge when subjected to bias-temperature test conditions of applied field of 2 X 106 V/cm for 30 minutes at 250*C, the improvement of adding HCl from an external source to said reactants.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said reaction mixture includes a carrier gas.
Claim 6
Dependent Claim
18 words
The method of claim 2 wherein the HCl represents from 0.1 to 3.0 mole-percent of the reaction mixture.
Claim 7
Dependent Claim
12 words
The method of claim 3 wherein said SiHnCl(4 n) reactant is silane.
Claim 8
Dependent Claim
11 words
The method of claim 4 wherein said oxidizing agent is CO2.
Claim 9
Dependent Claim
11 words
The method of claim 5 wherein said carrier gas is H2.
Claim 10
Dependent Claim
18 words
The method of claim 6 wherein said silicon dioxide film is formed over an integrated circuit silicon substrate.
Claim 11
Dependent Claim
25 words
The method of claim 4 wherein said chemical-vapor deposition reaction involves heating the film to a temperature of at least 700*C, during or after deposition.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |