US4133724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anodizing a compound semiconductor
Assignee: National Research Development Corp UK
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Filing: 1977-11-30
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Granted: 1979-01-09
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Expires: 1997-11-30
Abstract
Abstract A method of anodizing a compound semiconductor comprises (1) plating a metal on the compound semiconductor, (2) contacting the exposed surface of the metal with an electrolyte which permits anodic oxidation of the metal, and (3) passing an electric current through the electrolyte with the exposed surface of the metal acting as an anode, the current density not exceeding 100 microamps per square centimeter of the surface and the quantity of current being more than sufficient to oxidize anodically all the metal.
Inventors
- 👤 Hans L. Hartnagel
- 👤 Stephen J. Hannah
- 👤 Burhan Bayraktaroglu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:25
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6314; C; C25; C25D; C25D11/00; C25D11/02; C25D11/32; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69391; H10P14/69392; H10P14/69393; H10P14/69394; H10P14/69395; H10P14/6324
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
82 words
A method of anodising a compound semiconductor, comprising (1) plating a metal on the compound semiconductor, (2) contacting the exposed surface of the metal with an electrolyte which permits anodic oxidation of the metal, and (3) passing an electric current through the electrolyte with the exposed surface of the metal acting as an anode, the current density not exceeding 100 microamps per square centimeter of the surface and the quantity of current being more than sufficient to oxidise anodically all the metal.
Claim 2
Independent Claim
82 words
A method of anodising a compound semiconductor, comprising (1) plating a metal on the compound semiconductor, (2) contacting the exposed surface of the metal with an electrolyte which permits anodic oxidation of the metal, and (3) passing an electric current through the electrolyte with the exposed surface of the metal acting as an anode, the current density not exceeding 100 microamps per square centimeter of the surface and the quantity of current being more than sufficient to oxidise anodically all the metal.
Claim 3
Dependent Claim
19 words
A method according to claim 1, in which the current density does not exceed 10 microamps per square centimeter.
Claim 4
Dependent Claim
18 words
A method according to claim 1, wherein, during step (2), the compound semiconductor is protected from the electrolyte.
Claim 5
Dependent Claim
17 words
A method according to claim 1, wherein the plating of step (1) is performed by vapor deposition.
Claim 6
Dependent Claim
29 words
A method according to claim 1, wherein the quantity of current is such as to give at least 30A thickness of native semiconductor oxide underlying the anodically oxidised metal.
Claim 7
Dependent Claim
22 words
A method according to claim 1, wherein the compound semiconductor is a compound between a Group III and a Group V element.
Claim 8
Dependent Claim
13 words
A method according to claim 6, wherein the compound semiconductor is gallium arsenide.
Claim 9
Dependent Claim
14 words
A method according to claim 6, wherein the compound semiconductor is a single crystal.
Claim 10
Dependent Claim
20 words
A method according to claim 6, wherein the metal is one of tantalum, hafnium, zirconium, titaniun, zinc, nickel and aluminium.
Claim 11
Dependent Claim
18 words
A method according to claim 9, wherein the metal is plated to a thickness of at least 50A.
Claim 12
Independent Claim
85 words
A method of anodising a compound semicondctor, comprising (1) plating a metal on the compound semiconductor, (2) contacting the exposed surface of the metal with an electrolyte which permits anodic oxidation of the metal, and (3) passing an electric current through the electrolyte with the exposed surface of the metal acting as an anode, the current density exceeding 20 but not exceeding 100 microamps per square centimeter of the surface and the quantity of current being more than sufficient to oxidise anodically all the metal.
Claim 13
Independent Claim
85 words
A method of anodising a compound semicondctor, comprising (1) plating a metal on the compound semiconductor, (2) contacting the exposed surface of the metal with an electrolyte which permits anodic oxidation of the metal, and (3) passing an electric current through the electrolyte with the exposed surface of the metal acting as an anode, the current density exceeding 20 but not exceeding 100 microamps per square centimeter of the surface and the quantity of current being more than sufficient to oxidise anodically all the metal.
Claim 14
Independent Claim
82 words
A method of anodising a compound semiconductor, comprising (1) plating a metal on the compound semiconductor, (2) contacting the exposed surface of the metal with an electrolyte which permits anodic oxidation of the metal, and (3) passing an electric current through the electrolyte with the exposed surface of the metal acting as an anode, the current density not exceeding 20 microamps per square centimeter of the surface and the quantity of current being more than sufficient to oxidise anodically all the metal.
Claim 15
Independent Claim
82 words
A method of anodising a compound semiconductor, comprising (1) plating a metal on the compound semiconductor, (2) contacting the exposed surface of the metal with an electrolyte which permits anodic oxidation of the metal, and (3) passing an electric current through the electrolyte with the exposed surface of the metal acting as an anode, the current density not exceeding 20 microamps per square centimeter of the surface and the quantity of current being more than sufficient to oxidise anodically all the metal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-08 | 1982-07-10 | 1983-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-08 | 1986-07-10 | 1987-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-08 | 1990-07-10 | 1991-01-09 | $7700.00 | Window Closed / Lapsed |