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US3801391A
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Method for selectively etching alxga1-xas multiplier structures
Assignee: AT&T Inc
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Filing: 1972-09-25
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Granted: 1974-04-02
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Expires: 1992-09-25
Abstract
Abstract A method for selectively etching a layer of AlxGa1 xAs with a low concentration of Al in a multilayer structure while leaving adjacent layers of AlxGa1 xAs material of higher concentration Al relatively unaffected. The structure is immersed in an etchant consisting essentially of an H2O2 solution neutralized to a pH of 6-8 with a suitable hydroxide such as NH4OH. Preferably, the solution is agitated to insure that the etched surfaces are smooth. This selective etching technique may be used to form a variety of structures including a passive optical waveguide of extremely small dimensions.
Inventors
- 👤 J Dyment
- 👤 R Logan
- 👤 B Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:46
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646; Y; Y10; Y10S; Y10S148/00; Y10S148/051; Y10S148/065; Y10S148/072
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
15 words
The method according to claim 1 wherein x1 lies within the range 0 - 0.2.
Claim 2
Dependent Claim
14 words
The method according to claim 1 wherein x2 - x1 > or = 0.02.
Claim 3
Dependent Claim
14 words
The method according to claim 1 wherein x2 - x1 > or = 0.085.
Claim 4
Dependent Claim
19 words
The method according to claim 1 wherein the concentration of H2O2 is within the range 10-70 percent by weight.
Claim 5
Dependent Claim
16 words
The method according to claim 1 wherein the concentration of H2O2 is 30 percent by weight.
Claim 6
Dependent Claim
14 words
The method according to claim 1 wherein the source of hydroxyl ions is NH4OH.
Claim 7
Dependent Claim
20 words
The method according to claim 1 further comprising the step of agitating the solution while the device is immersed therein.
Claim 8
Dependent Claim
20 words
The method according to claim 8 wherein the solution is agitated by rotating the device while immersed is said solution.
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) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |