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US4100014A
Expired / Lapsed
US
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Etching agent for III/V semiconductors
Assignee: Siltronic AG
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Filing: 1977-04-06
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Granted: 1978-07-11
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Expires: 1997-04-06
Abstract
Abstract An etching agent for III/V semiconductor material consisting of (a) 1 to 30 percent by weight of hydrofluoric acid, (b) 2 to 30 percent by weight of hydrogen peroxide, (c) 1 to 75 percent by weight of sulfuric acid, (d) 15 to 95 percent by weight of water, Wherein the quantities by weight of the individual components are so chosen that they will add up to 100 percent by weight.
Inventors
- 👤 Franz Kuhn-Kuhnenfeld
- 👤 Dietmar Kirsten
- 👤 Marianne Maier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:41
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
83 words
A polishing dislocation etchant for Ga As x P 1-x where x is in the range between 0 and 1 consisting of: (a) 1 to 30 percent by weight of hydrofluoric acid; (b) 2 to 30 percent by weight of hydrogen peroxide; (c) 1 to 75 percent by weight of sulfuric acid; (d) 15 to 95 percent by weight of water; wherein the quantities by weight of the individual components are so chosen that they will add up to 100 percent by weight.
Claim 2
Dependent Claim
83 words
A polishing dislocation etchant for Ga As x P 1-x where x is in the range between 0 and 1 consisting of: (a) 1 to 30 percent by weight of hydrofluoric acid; (b) 2 to 30 percent by weight of hydrogen peroxide; (c) 1 to 75 percent by weight of sulfuric acid; (d) 15 to 95 percent by weight of water; wherein the quantities by weight of the individual components are so chosen that they will add up to 100 percent by weight.
Claim 3
Dependent Claim
18 words
The etchant according to claim 1, wherein the content of hydrofluoric acid is 6 - 18% by weight.
Claim 4
Dependent Claim
18 words
The etchant according to claim 1, wherein the content of hydrogen peroxide is 6 - 20% by weight.
Claim 5
Dependent Claim
18 words
The etchant according to claim 1, wherein the content of sulfuric acid is 20 - 55% by weight.
Claim 6
Dependent Claim
17 words
The etchant according to claim 1, wherein the content of water is 30 - 55% by weight.
Claim 7
Dependent Claim
37 words
A process of preparing the etchant according to claim 1, wherein the hydrofluoric acid and the hydrogen peroxide are first mixed in aqueous solution, and in a second step concentrated sulfuric acid is slowly added while stirring.
Claim 8
Dependent Claim
39 words
The etchant prepared according to claim 6, consisting of a mixture of two parts by volume of 40% weight hydrofluoric acid, two parts by volume of 30% weight hydrogen peroxide, and three parts by volume of concentrated sulfuric acid.
Claim 9
Dependent Claim
39 words
The etchant prepared according to claim 6, consisting of a mixture of one part by volume of 40% weight hydrofluoric acid, four parts by volume of 30% weight hydrogen peroxide, and one part by volume of concentrated sulfuric acid.
Claim 10
Dependent Claim
40 words
The etchant prepared according to claim 6, consisting of a mixture of two parts by volume of 40% weight hydrofluoric acid, one part by volume of 30 percent weight hydrogen peroxide, and one part by volume of concentrated sulfuric acid.
Claim 11
Dependent Claim
108 words
An improved method for producing etch pits to expose dislocations on the surface of Ga As x P 1-x semiconductors, wherein x is in the range between 0 and 1, comprising the step of: treating the surface of said semiconductors with a polishing dislocation etchant consisting of (a) 1 to 30 percent by weight of hydrofluoric acid; (b) 2 to 30 percent by weight of hydrogen peroxide; (c) 1 to 75 percent by weight of sulfuric acid; (d) 15 to 95 percent by weight of water; wherein the quantities by weight of the individual components are so chosen that they will add up to 100 percent by weight.
Claim 12
Dependent Claim
108 words
An improved method for producing etch pits to expose dislocations on the surface of Ga As x P 1-x semiconductors, wherein x is in the range between 0 and 1, comprising the step of: treating the surface of said semiconductors with a polishing dislocation etchant consisting of (a) 1 to 30 percent by weight of hydrofluoric acid; (b) 2 to 30 percent by weight of hydrogen peroxide; (c) 1 to 75 percent by weight of sulfuric acid; (d) 15 to 95 percent by weight of water; wherein the quantities by weight of the individual components are so chosen that they will add up to 100 percent by weight.
Claim 13
Dependent Claim
18 words
The method according to claim 10, wherein the content of hydrofluoric acid is 6 - 18% by weight.
Claim 14
Dependent Claim
18 words
The method according to claim 10, wherein the contents of hydrogen peroxide is 6 - 20% by weight.
Claim 15
Dependent Claim
18 words
The method according to claim 10, wherein the content of sulfuric acid is 20 - 55% by weight.
Claim 16
Dependent Claim
17 words
The method according to claim 10, wherein the content of water is 30 - 55% by weight.
References Cited (Backward Citations)
GB989025A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |