US3615955A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for polishing a silicon surface
Assignee: International Business Machines Corp
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Filing: 1969-02-28
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Granted: 1971-10-26
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Expires: 1989-02-28
Abstract
Abstract A silicon surface is polished by a simultaneous application of mechanical and chemical polishing procedures. The silicon surface to be polished is maintained continuously wetted with an excess quantity of a displacement plating solution containing a mercury cation and a fluoride anion. Mercury is deposited on the surface by the displacement of silicon and a simultaneous and continuous wiping of the surface removes the mercury from the high areas on the silicon surface.
Inventors
- 👤 Joseph Regh
- 👤 Gene A Silvey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:43
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/129; B; B24; B24B; B24B37/00; B24B37/04; B24B37/07; B24B37/10; B24B37/102; C; C23; C23F; C23F3/00; C23F3/04; C23F3/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
39 words
The method of claim 1 wherein the said solution is aqueous; the mercury cation is brought into the said solution by use of mercury nitrate; and the fluoride anion is brought into said solution by use of ammonium fluoride.
Claim 2
Dependent Claim
27 words
The method of claim 1 wherein the said silicon impurity is arsenic or antimony and the solution is maintained at a pH between about 5 to 7.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein the said pressure applied is above about 1 pound per square inch.
Claim 4
Dependent Claim
29 words
The method of claim 1 wherein the said silicon surface is planar and is one face of a silicon wafer and said firm surface is a supported paper layer.
Claim 5
Dependent Claim
30 words
The method of claim 1 wherein the said silicon surface is planar and is one face of a silicon wafer and said firm surface is a supported napped cloth layer.
Claim 6
Independent Claim
199 words
A method for polishing a monocrystalline silicon planar surface to a high-degree of surface perfection suitable for epitaxial deposition wherein the silicon planar surface can have an impurity concentration higher than 1 X 1018 atoms/cc. comprising: maintaining the said silicon surface continuously wetted with an excess quantity of an aqueous displacement plating solution having a PH less than 7 containing a mercury cation and a fluoride anion to cause a displacement plating of mercury onto the said silicon surface; the said fluoride anion is maintained in excess quantities to said mercury cation which is present in quantity sufficient for the desired polishing rate; continuously wiping the said silicon surface with a soft, firm surface using a pressure greater than about 1 pound per square inch while maintaining a relative rotating movement between the said silicon surface and the said soft surface to remove the said mercury from the high-points of said silicon surface; and after the said silicon surface has been adequately polished, replacing said plating solution with a nonplating medium wetting the said silicon surface to prevent further polishing and allow said firm surface to remove the maximum amount of said mercury possible from said polished silicon surface.
Claim 7
Dependent Claim
50 words
The method of claim 7 wherein the said solution is aqueous; the mercury cation is brought into the said solution by use of mercury nitrate; the fluoride anion is brought into said solution by use of ammonium fluoride; and the said solution pH is maintained between about 5 and 7.
Claim 8
Dependent Claim
27 words
The method of claim 7 wherein the said planar silicon surface is one faCe of a silicon wafer and said firm surface is a supported paper layer.
Claim 9
Dependent Claim
28 words
The method of claim 7 wherein the said planar silicon surface is one face of a silicon wafer and said firm surface is a supported napped cloth layer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |