Patent US4705593A successfully refreshed from Google Patents.
US4705593A
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Etching method
Assignee: British Telecommunications PLC
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Filing: 1986-06-26
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Granted: 1987-11-10
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Expires: 2006-06-26
Abstract
Abstract Materials whose elemental constituents are selected from groups III and V of the Periodic Table are photochemically etched in a reducing environment. Etching is carried out by illuminating a halogenated hydrocarbon gas, e.g. methyl iodide, with ultra-violet light in the vicinity of the material. The reducing environment is provided by the presence of sufficient hydrogen to suppress the effect of any oxygen leaking into the system. Methods according to the invention may be used in particular in the production of opto-electronic devices.
Inventors
- 👤 John Haigh
- 👤 Martin R. Aylett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:42
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/246
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
34 words
A method of etching a surface, whose elemental constituents are selected from Groups III and V of the Periodic Table, which method comprises exposing the surface to free halide radicals in a reducing environment.
Claim 2
Independent Claim
34 words
A method of etching a surface, whose elemental constituents are selected from Groups III and V of the Periodic Table, which method comprises exposing the surface to free halide radicals in a reducing environment.
Claim 3
Dependent Claim
34 words
A method according to claim 1, wherein the free halide radicals are provided by the illumination of a halide gas by light having a wavelength which allows it to be absorbed by the gas.
Claim 4
Independent Claim
74 words
A method of etching a pattern onto an exposed surface of a wholly or partly formed opto-electronic device, said surface being on a layer of III-V semiconductor, which method comprises exposing the surface to a reducing atmosphere which contains a halogen gas while illuminating the surface in the desired pattern with radiation adapted to dissociate said halogen gas into halogen radicals which react with the surface whereby the surface is etched with the pattern.
Claim 5
Independent Claim
74 words
A method of etching a pattern onto an exposed surface of a wholly or partly formed opto-electronic device, said surface being on a layer of III-V semiconductor, which method comprises exposing the surface to a reducing atmosphere which contains a halogen gas while illuminating the surface in the desired pattern with radiation adapted to dissociate said halogen gas into halogen radicals which react with the surface whereby the surface is etched with the pattern.
Claim 6
Dependent Claim
22 words
A method according to claim 3, wherein the illumination comprises traversing a spot of radiation over the surface in the desired pattern.
Claim 7
Dependent Claim
14 words
A method according to claim 4, wherein the light is provided by a laser.
Claim 8
Dependent Claim
27 words
A method according to claim 5, wherein a diffraction grating is etched on the exposed surface, which comprises traversing the spot in a series of parallel lines.
Claim 9
Dependent Claim
17 words
A method according to claim 3, wherein the reducing environment is provided by the presence of hydrogen.
Claim 10
Dependent Claim
14 words
A method according to claim 3, wherein the halide gas comprises a halogenated hydrocarbon.
Claim 11
Dependent Claim
14 words
A method according to claim 8, wherein the halide gas is a methyl halide.
Claim 12
Dependent Claim
13 words
A method according to claim 9, wherein the methyl halide is methyl iodide.
Claim 13
Dependent Claim
38 words
A method according to claim 3, in which the etched material is a compound of at least one element selected from In, Ga and Al with at least one element selected from P and As together with dopants.
Claim 14
Dependent Claim
25 words
A method of manufacturing an opto-electronic device which comprises a shaped interface wherein the shaped interface was etched by a method according to claim 3.
Claim 15
Dependent Claim
31 words
A method of manufacturing a distributed feedback laser which laser includes a diffraction grating, wherein said method includes the step of forming said grating by a method according to claim 6.
Claim 16
Independent Claim
48 words
A method of etching a surface on a layer of III-V semiconductor, which method comprises exposing the surface to an atmosphere of hydrogen and a halogenated hydrocarbon while illuminating the surface with radiation adapted to dissociate said halogenated hydrocarbon into halogen radicals which react and etch the surface.
Claim 17
Independent Claim
48 words
A method of etching a surface on a layer of III-V semiconductor, which method comprises exposing the surface to an atmosphere of hydrogen and a halogenated hydrocarbon while illuminating the surface with radiation adapted to dissociate said halogenated hydrocarbon into halogen radicals which react and etch the surface.
Claim 18
Dependent Claim
14 words
A method according to claim 8, wherein the halogenated hydrocarbon is a methyl halide.
Claim 19
Dependent Claim
13 words
A method according to claim 15, wherein the methyl halide is methyl iodide.
Claim 20
Dependent Claim
38 words
A method according to claim 16, in which the etched material is a compound of at least one element selected from In, Ga and Al with at least one element selected from P and As together with dopants.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |