US3869324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of polishing cadmium telluride
Assignee: International Business Machines Corp
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Filing: 1973-12-28
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Granted: 1975-03-04
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Expires: 1993-12-28
Abstract
Abstract Cadmium telluride with damage-free surfaces is obtained by chemically-mechanically polishing using a chemical polishing system including a stable, water soluble alkali metal or alkaline earth metal hypohalite and an alkali metal carbonate; the alkali metal carbonate must be present in at least equimolar proportions to the hypohalite.
Inventors
- 👤 Jagtar Singh Basi
- 👤 Eric Mendel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:06
CPC Classifications
H; H10; H10P; H10P50/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
106 words
A METHOD FOR THE CHEMICAL-MECHANICAL POLISHING OF A CADMIUM TELLURIDE SURFACE TO A HIGH DEGREE OF SURFACE PERFECTION COMPRISING: MAINTAINING SAID CADMIUM TELLURIDE SURFACE CONTINUOUSLY WETTED WITH AN EXCESS QUANTITY OF AN AQUEOUS CHEMICAL POLISHING SOLUTION COMPRISING AN ALKALI METAL OR ALKALINE EARTH METAL HYPOHALITE AND AN ALKALI METAL CARBONATE, THE ALKALI METAL CARBONATE BEING AT LEAST EQUIMOLAR TO THE ALKALI METAL HYPOHALITE; AND CONTINUOUSLY WIPING THE CADMIUM TELLURIDE SURFACE WITH A FIRM SURFACE USING A SUBSTANTIAL PRESSURE WHILE MAINTAINING A RELATIVE MOVEMENT BETWEEN THE CADMIUM TELLURIDE SURFACE AND THE FIRM SURFACE TO REMOVE THE CADMIUM TELLURIDE FROM THE HIGH POINTS OF THE CADMIUM TELLURIDE SURFACE.
Claim 2
Independent Claim
106 words
A METHOD FOR THE CHEMICAL-MECHANICAL POLISHING OF A CADMIUM TELLURIDE SURFACE TO A HIGH DEGREE OF SURFACE PERFECTION COMPRISING: MAINTAINING SAID CADMIUM TELLURIDE SURFACE CONTINUOUSLY WETTED WITH AN EXCESS QUANTITY OF AN AQUEOUS CHEMICAL POLISHING SOLUTION COMPRISING AN ALKALI METAL OR ALKALINE EARTH METAL HYPOHALITE AND AN ALKALI METAL CARBONATE, THE ALKALI METAL CARBONATE BEING AT LEAST EQUIMOLAR TO THE ALKALI METAL HYPOHALITE; AND CONTINUOUSLY WIPING THE CADMIUM TELLURIDE SURFACE WITH A FIRM SURFACE USING A SUBSTANTIAL PRESSURE WHILE MAINTAINING A RELATIVE MOVEMENT BETWEEN THE CADMIUM TELLURIDE SURFACE AND THE FIRM SURFACE TO REMOVE THE CADMIUM TELLURIDE FROM THE HIGH POINTS OF THE CADMIUM TELLURIDE SURFACE.
Claim 3
Dependent Claim
10 words
The process of claim 1, where the hypohalite is hypobromite.
Claim 4
Dependent Claim
11 words
The process of claim 2, where the alkali metal is sodium.
Claim 5
Dependent Claim
26 words
The process of claim 3, where sodium hypobromite is present at a concentration from about 0.2 molar to about 0.8 molar in the chemical polishing solution.
Claim 6
Dependent Claim
23 words
The process of claim 4, where the sodium hypobromite is present at a concentration of about 0.4 molar in the chemical polishing solution.
Claim 7
Dependent Claim
21 words
The process of claim 5, where the firm pressure is from about 80 to about 100 gm/cm2 of cadmium telluride surface.
Claim 8
Dependent Claim
17 words
The process of claim 6, where the pH of the chemical polishing solution is above about 8.
Claim 9
Dependent Claim
34 words
The process of claim 7, where the chemical polishing solution is flowed over the cadmium telluride at a rate of about 4 to about 50 ml/min. per micron of cadmium telluride to be removed.
Claim 10
Dependent Claim
11 words
The process of claim 1, where the cadmium telluride is polycrystalline.
Claim 11
Dependent Claim
12 words
The process of claim 1, where the cadmium telluride is single crystal.
References Cited (Backward Citations)
US2690383A
Cited
US2822250A
Cited
US3143447A
Cited
US3342652A
Cited
US3429756A
Cited
US3629023A
Cited
US3775201A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |