Patent US4300989A successfully refreshed from Google Patents.
US4300989A
Expired / Lapsed
US
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Fluorine enhanced plasma growth of native layers on silicon
Assignee: AT&T Inc
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Filing: 1979-10-03
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Granted: 1981-11-17
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Expires: 1999-10-03
Abstract
Abstract The plasma growth rate of native layers, such as oxide and nitride, on silicon is enhanced by the addition of fluorine. An increase in growth rate is obtained, and the oxide growth rates on doped and undoped portions of the silicon substrate are substantially the same. The fluorine is typically added by means of a fluorinated compound, typically CF 4 , comprising 0.01 to 5 molecular percent of the plasma. Lower substrate temperatures, typically less than 600 degrees C., may be used, resulting in less warpage of the wafer and less diffusion of dopants.
Inventors
- 👤 Robert P. H. Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:45
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6316; H10P14/6319; H10P14/69; H10P14/692; H10P14/6921; H10P14/6922; H10P14/6924; H10P14/694; H10P14/6943; H10P14/69433
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
141 words
A method of making a semiconductor device including the step of growing a native layer at least 50 Angstroms thick on a body comprising silicon by steps comprising exposing said body to a plasma comprising a concentration of at least 10 9 electrons per cubic centimeter adjacent to the surface of said native layer, and placing said body at a positive electrical potential with respect to the source of said plasma, characterized in that said plasma comprises fluorine which provides for the incorporation of atomic fluorine in said native layer during said growing, with the concentration of said fluorine in said plasma being less than a concentration which produces etching of said native layer, and with said fluorine producing an increase in the growth rate of said native layer as compared to the growth rate in the absence of said fluorine.
Claim 2
Independent Claim
141 words
A method of making a semiconductor device including the step of growing a native layer at least 50 Angstroms thick on a body comprising silicon by steps comprising exposing said body to a plasma comprising a concentration of at least 10 9 electrons per cubic centimeter adjacent to the surface of said native layer, and placing said body at a positive electrical potential with respect to the source of said plasma, characterized in that said plasma comprises fluorine which provides for the incorporation of atomic fluorine in said native layer during said growing, with the concentration of said fluorine in said plasma being less than a concentration which produces etching of said native layer, and with said fluorine producing an increase in the growth rate of said native layer as compared to the growth rate in the absence of said fluorine.
Claim 3
Dependent Claim
29 words
The method of claim 1 further characterized in that the atomic concentration of fluorine in the native layer as grown is in the range of 0.001 to 0.5 percent.
Claim 4
Dependent Claim
23 words
The method of claim 1 further characterized in that said plasma is an oxygen plasma, and said native layer is substantially silicon dioxide.
Claim 5
Dependent Claim
24 words
The method of claim 1 further characterized in that said plasma comprises nitrogen, and said native layer comprises a compound of silicon and nitrogen.
Claim 6
Independent Claim
28 words
The method of claims 1, 2, 3, or 4 further characterized in that the temperature of said body during said plasma exposure is less than 600 degrees C.
Claim 7
Dependent Claim
33 words
The method of claim 5 further characterized in that said body further comprises regions exposed to said plasma which differ in p-type or n-type doping levels by at least a factor of 10.
Claim 8
Dependent Claim
12 words
A semiconductor device made in accordance with the method of claim 6.
Claim 9
Independent Claim
24 words
The method of claims 1, 2, 3, or 4 further characterized in that said fluorine comprises at least 0.01 molecular percent of said plasma.
Claim 10
Dependent Claim
25 words
The method of claim 8 further characterized in that the source of said fluorine is introduced in said plasma by means of CF 4 .
Claim 11
Dependent Claim
20 words
The method of claim 8 further characterized in that said fluorine comprises less than 5 molecular percent of said plasma.
Claim 12
Dependent Claim
31 words
The method of claim 1 further characterized in that the increased growth rate produced by said fluorine is at least four times the growth rate in the absence of said fluorine.
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) | 1984-11-16 | 1985-05-18 | 1985-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-16 | 1989-05-18 | 1989-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-16 | 1993-05-18 | 1993-11-17 | $7700.00 | Window Closed / Lapsed |