US4194954A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic etch preparation of semiconductor surfaces
Assignee: Post Office
•
Filing: 1978-03-08
•
Granted: 1980-03-25
•
Expires: 1998-03-08
Abstract
Abstract The surface of a semiconductor is prepared by electrolytically removing the surface of the semiconductor. A two component electrolyte is used. A first component forms an oxide on the surface of the semiconductor and the second component dissolves the oxide.
Inventors
- 👤 Marc M. Faktor
- 👤 John L. Stevenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:23
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6312; C; C25; C25F; C25F3/00; C25F3/02; C25F3/12; H10P50/00; H10P50/60; H10P50/61; H10P50/617; H10P14/6324
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
65 words
A method of preparing a surface of a semiconductor by etching with a two-component electrolyte comprising: immersing a semiconductor and a spaced electrode in a two component non-aqueous electrolyte and establishing a potential between said semiconductor and said electrode; forming an oxide coating on the semiconductor with a first component of the electrolyte; and dissolving said oxide coating with the second component of the electrolyte.
Claim 2
Independent Claim
65 words
A method of preparing a surface of a semiconductor by etching with a two-component electrolyte comprising: immersing a semiconductor and a spaced electrode in a two component non-aqueous electrolyte and establishing a potential between said semiconductor and said electrode; forming an oxide coating on the semiconductor with a first component of the electrolyte; and dissolving said oxide coating with the second component of the electrolyte.
Claim 3
Dependent Claim
24 words
A method as claimed in claim 1 wherein said electrolyte comprises sodium dihydrogen orthophosphate as the first component and tiron as the second component.
Claim 4
Dependent Claim
13 words
A method as claimed in claim 2 wherein the semiconductor is gallium arsenide.
Claim 5
Dependent Claim
21 words
A method as claimed in claim 2 wherein the proportion of tiron is less than or equal to 20% by volume.
Claim 6
Dependent Claim
25 words
A method as claimed in claim 4 wherein the proportion of tiron is approximately 15% and the proportion of sodium dihydrogen orthophosphate is approximately 85%.
Claim 7
Dependent Claim
24 words
A method as claimed in claim 1 wherein the method is started with said first component alone and the second component is added subsequently.
Claim 8
Dependent Claim
19 words
A method as claimed in claim 1 wherein the two components are mixed prior to electrolytic action being commenced.
Claim 9
Dependent Claim
33 words
A method as claimed in claim 1 wherein the first component is one of sodium dihydrogen orthophosphate, disodium tetraborate and potassium dihydrogen arsenate and the second component is one of tiron and ethanolamine.
Claim 10
Dependent Claim
43 words
An electrolyte for use in the method as claimed in claim 1 said electrolyte comprising two components, one of which can form an oxide layer on the surface of the semiconductor to be prepared, and the other of which can dissolve the oxide.
Claim 11
Dependent Claim
20 words
An electrolyte as claimed in claim 9 wherein the proportion of the second component is 20% or less by volume.
Claim 12
Dependent Claim
33 words
An electrolyte as claimed in claim 9 wherein the first component is one of sodium dihydrogen orthophosphate, disodium tetraborate and potassium dihydrogen arsenate and the second component is one of tiron and ethanolamine.
Claim 13
Dependent Claim
29 words
An electrolyte as claimed in claim 9 wherein the first component is approximately 85% by volume sodium dihydrogen orthophosphate and the second component is approximately 15% by volume tiron.
References Cited (Backward Citations)
US3010885A
Cited
NL249127A
Cited
US3798139A
Cited
US3929589A
Cited
US4006047A
Cited
US4026741A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-03-25 | 1983-09-24 | 1984-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-25 | 1987-09-24 | 1988-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-25 | 1991-09-24 | 1992-03-25 | $7700.00 | Window Closed / Lapsed |