US3979239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for chemical-mechanical polishing of III-V semiconductor materials
Assignee: Monsanto Co
•
Filing: 1974-12-30
•
Granted: 1976-09-07
•
Expires: 1994-12-30
Abstract
Abstract Method for combined chemical-mechanical polishing of III - V semiconductor planar surfaces by applying a weak aqueous hydrochloric acid solution in combination with an aqueous source of chlorine to the surface to be polished while simultaneously mechanically polishing the surface.
Inventors
- 👤 Robert J. Walsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:51
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/129; Y; Y10; Y10S; Y10S438/00; Y10S438/959
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
42 words
A process for polishing a surface of a III - V semiconductor compound, comprising mechanically polishing said surface while applying thereto in an acid environment an etchant concentration of an aqueous solution of a compound which yields free chlorine under acid conditions.
Claim 2
Dependent Claim
42 words
A process for polishing a surface of a III - V semiconductor compound, comprising mechanically polishing said surface while applying thereto in an acid environment an etchant concentration of an aqueous solution of a compound which yields free chlorine under acid conditions.
Claim 3
Dependent Claim
47 words
The process of claim 1 wherein (A) an aqueous solution of an acid and (B) an aqueous solution of an alkali metal hypochlorite, an aqueous solution of a chlorinated cyanuric acid or salt thereof, or mixtures thereof, are combined to form said etchant in an acid environment.
Claim 4
Dependent Claim
19 words
The process of claim 2 wherein said solutions are applied as separate streams and mixed during said mechanical polishing.
Claim 5
Dependent Claim
20 words
The process of claim 3 wherein sodium hypochlorite or potassium hypochlorite is used, and wherein said acid is hydrochloric acid.
Claim 6
Dependent Claim
10 words
The process of claim 3 wherein trichlorocyanuric acid is used.
Claim 7
Dependent Claim
15 words
The process of claim 3 wherein the alkali metal salt of dichlorocyanuric acid is used.
Claim 8
Dependent Claim
22 words
The process of claim 4 wherein the concentration of the aqueous hydrochloric acid solution is about 0.5 to about 2 weight %.
Claim 9
Dependent Claim
20 words
The process of claim 5 wherein the concentration of the aqueous hydrochloric solution is about 0.5 to 2 weight %.
Claim 10
Dependent Claim
19 words
The process of claim 6 wherein the concentration of the aqueous hydrochloric acid solution is about 0.5 to 2%.
Claim 11
Dependent Claim
21 words
The process of claim 7 wherein the concentration of the aqueous sodium or potassium hypochlorite solution is about 0.5 to 5.0%.
Claim 12
Dependent Claim
32 words
The process of claim 10 wherein the hydrochloric acid is used in a concentration of about 1.25% and the sodium hypochlorite or potassium hypochlorite is used in a concentration of about 3%.
Claim 13
Dependent Claim
22 words
The process of claim 8 wherein the cyanuric acid or salt thereof is used in a concentration of about 0.5 to 5.0%.
Claim 14
Dependent Claim
30 words
The process of claim 12 wherein the hydrochloric acid is used in a concentration of about 1.25% and the potassium dichlorocyanuric acid is used in a concentration of about 3.0%.
Claim 15
Dependent Claim
48 words
The process of claim 10 wherein said mechanical polishing is carried out by providing a relative motion between said surface and a polishing surface while applying a pressure of about 1 to 100 pounds per square inch of said surface to press the surface against said polishing surface.
Claim 16
Dependent Claim
50 words
The process of claim 12 wherein said mechanical polishing is carried out by providing a relative motion between said semiconductor surface and a polishing surface while applying a pressure of about 1 to 100 pounds per square inch of said surface to press said semiconductor surface against said polishing surface.
Claim 17
Dependent Claim
29 words
The process of claim 10 wherein the flow rates of the hydrochloric acid and hypochlorite solution are 50 to 100 milliliters per minute per square inch of said surface.
Claim 18
Dependent Claim
32 words
The process of claim 12 wherein the flow rates of the hydrochloric acid and cyanuric salt or acid solutions are 50 to 100 milliliters per minute per square inch of said surface.
References Cited (Backward Citations)
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US3615955A
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US3775201A
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US3791948A
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US3869323A
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US3869324A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |