US4007294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating a layer of silicon dioxide
Assignee: RCA Corp
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Filing: 1976-03-08
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Granted: 1977-02-08
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Expires: 1996-03-08
Abstract
Abstract A layer of silicon dioxide such as used in an MOS gate dielectric, is treated, after growth, to prevent deleterious effects resulting from any mobile impurity ions therein. An ionic fluoride compound is applied to one surface of the layer of silicon dioxide. A corona discharge is then directed from a negative electrode of a pair of electrodes of opposite polarity onto the fluoride compound to drive the fluoride ions into the layer. The layer is then washed and annealed.
Inventors
- 👤 Murray Henderson Woods
- 👤 Richard Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:12
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/20; H10D; H10D64/00; H10D64/01; H10D64/011; H10D99/00; H10P95/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
92 words
A method of treating a layer of silicon dioxide having a pair of opposite surfaces comprising the steps of: applying an ionic fluoride compound to one surface of said layer of silicon dioxide, and directing a corona discharge onto said one surface between a negative electrode spaced from said one surface of said silicon dioxide layer, and the other surface of said silicon dioxide layer which is connected to a source of potential more positive than said negative electrode to drive fluoride ions of said compound into said layer of silicon dioxide.
Claim 2
Independent Claim
92 words
A method of treating a layer of silicon dioxide having a pair of opposite surfaces comprising the steps of: applying an ionic fluoride compound to one surface of said layer of silicon dioxide, and directing a corona discharge onto said one surface between a negative electrode spaced from said one surface of said silicon dioxide layer, and the other surface of said silicon dioxide layer which is connected to a source of potential more positive than said negative electrode to drive fluoride ions of said compound into said layer of silicon dioxide.
Claim 3
Dependent Claim
71 words
A method as recited in claim 1 wherein the step of applying said ionic fluoride compound to said one surface of said silicon dioxide layer is performed by: coating said one surface of said silicon dioxide layer with a solution of a solute of said ionic fluoride compound in a solvent, and drying said solution to remove said solvent, whereby said solute of ionic fluoride compound remains on said one surface.
Claim 4
Dependent Claim
32 words
A method as recited in claim 2 wherein: said solute consists of a salt chosen from the group consisting of potassium fluoride, sodium fluoride, and ammonium fluoride, and said solvent comprises water.
Claim 5
Dependent Claim
35 words
A method as recited in claim 2 wherein the step of drying said solution is performed by placing said silicon dioxide layer in a desiccator to remove said solvent from said solution at room temperature.
Claim 6
Dependent Claim
46 words
A method as recited in claim 1 wherein the step of applying said ionic fluoride compound to said one surface of said silicon dioxide layer is performed by vapor depositing a layer of said ionic fluoride compound onto said one surface of said silicon dioxide layer.
Claim 7
Dependent Claim
30 words
A method as recited in claim 5 wherein said ionic fluoride compound is a salt chosen from the group consisting of magnesium fluoride, potassium fluoride, sodium fluoride, and ammonium fluoride.
Claim 8
Dependent Claim
22 words
A method as recited in claim 5 wherein the thickness of said vapor-deposited layer of said ionic fluoride compound is about 200A.
Claim 9
Dependent Claim
34 words
A method as recited in claim 1 further comprising the steps of washing off said ionic fluoride compound with deionized water after performing the step of directing said corona discharge onto said one surface.
Claim 10
Dependent Claim
30 words
A method as recited in claim 8 further comprising the step of annealing said silicon dioxide layer at a temperature of at least 180° C for at least 15 minutes.
Claim 11
Dependent Claim
24 words
A method as recited in claim 1 wherein the step of directing said corona discharge onto said one surface is carried out in air.
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) | 1980-02-08 | 1980-08-09 | 1981-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-08 | 1984-08-09 | 1985-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-08 | 1988-08-09 | 1989-02-08 | $7700.00 | Window Closed / Lapsed |