EP0261408A2
Expired / Lapsed
EP
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Laser including monolithically integrated planar devices and processes for their preparation
Assignee: Eastman Kodak Co
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Filing: 1987-08-21
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Granted: —
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Expires: 2007-08-21
Abstract
Abstract Monolithically integrated devices are disclosed in which a laser having a capping layer with a relatively high conductivity imparting ion concentration is laterally offset along a planar surface from a surface layer having a lower conductivity imparting ion concentration. The monolithically integrated layer and surface layer are formed by providing laterally offset channels in a planar substrate surface and selectively epitaxially growing the required laser layers and the surface layer in separate channels.
Inventors
- 👤 Frank Thomas John Eastman Kodak Company Smith
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 10:03
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/02; H01S5/026; H01S5/20; H01S5/22; H01S5/227; H01S5/30; H01S5/32; H01S5/0201; H01S5/0205; H01S5/04; H01S5/042; H01S5/0421; H01S5/0422; H01S5/2201; H01S5/2275
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
340 words
A process comprising (i) providing a monocrystalline substrate, epitaxially growing on said substrate a laterally restricted lasing region comprising superimposed P and N conductivity type cladding layers, an active layer therebetween, and a capping layer adjacent said major surface having greater than 10¹⁹ conductivity imparting ions per cm³, (ii) laterally offset from said lasing region providing on said substrate a semiconductive surface layer having a conductivity imparting ion concentration less that that of said capping layer, said substrate and said layers together forming a monocrystalline III-V compound structure, wherein the group V ions are arsenic and the group III ions are at least one of gallium and aluminum, and (iii) ions are at least one of gallium and aluminum, and (iii) providing conductive means at said compound structure surface for providing a conduction path between said surface layer and said capping layer, characterized in that (a) said substrate adjacent one major surface intended to separate said lasing region and said surface layer is formed of monocrystalline gallium aluminum arsenide having a resistivity greater than 10⁵ ohm-cm and (b) said capping layer, said surface layer, and said separating substrate surface are formed to present a planar surface by the steps including (c) providing on said one major surface a protective layer defining an opening, (d) through the opening creating a channel in said substrate to expose an unprotected portion of said substrate beneath said one major surface, (e) epitaxially depositing said laser region layers on only said unprotected substrate por tion, at least said active layer being comprised of gallium arsenide or gallium aluminum arsenide of a higher refractive index than said substrate monocrystalline gallium aluminum arsenide, (f) terminating epitaxial deposition when said lasing region forms with said one major surface an overall planar surface, (g) forming said surface layer to present a planar surface with said substrate at a location laterally offset from said lasing region, and (h) depositing on said planar surface at least one conductive means providing a conduction path between said surface layer and said capping layer.
Claim 2
Dependent Claim
340 words
A process comprising (i) providing a monocrystalline substrate, epitaxially growing on said substrate a laterally restricted lasing region comprising superimposed P and N conductivity type cladding layers, an active layer therebetween, and a capping layer adjacent said major surface having greater than 10¹⁹ conductivity imparting ions per cm³, (ii) laterally offset from said lasing region providing on said substrate a semiconductive surface layer having a conductivity imparting ion concentration less that that of said capping layer, said substrate and said layers together forming a monocrystalline III-V compound structure, wherein the group V ions are arsenic and the group III ions are at least one of gallium and aluminum, and (iii) ions are at least one of gallium and aluminum, and (iii) providing conductive means at said compound structure surface for providing a conduction path between said surface layer and said capping layer, characterized in that (a) said substrate adjacent one major surface intended to separate said lasing region and said surface layer is formed of monocrystalline gallium aluminum arsenide having a resistivity greater than 10⁵ ohm-cm and (b) said capping layer, said surface layer, and said separating substrate surface are formed to present a planar surface by the steps including (c) providing on said one major surface a protective layer defining an opening, (d) through the opening creating a channel in said substrate to expose an unprotected portion of said substrate beneath said one major surface, (e) epitaxially depositing said laser region layers on only said unprotected substrate por tion, at least said active layer being comprised of gallium arsenide or gallium aluminum arsenide of a higher refractive index than said substrate monocrystalline gallium aluminum arsenide, (f) terminating epitaxial deposition when said lasing region forms with said one major surface an overall planar surface, (g) forming said surface layer to present a planar surface with said substrate at a location laterally offset from said lasing region, and (h) depositing on said planar surface at least one conductive means providing a conduction path between said surface layer and said capping layer.
Claim 3
Dependent Claim
32 words
A process according to claim 1 wherein said substrate includes a more conductive portion spaced from said one major surface and said channel extending into said substrate to said more conductive portion.
Claim 4
Dependent Claim
30 words
A process according to claim 1 or 2 in which said substrate presents a {100} crystal face and a longitudinal axis of said channel is formed along a <110> vector.
Claim 5
Dependent Claim
24 words
A process according to claim 3 in which at least one of the channels is formed with side walls lying in {111} crystal planes.
Claim 6
Dependent Claim
21 words
A process according to claim 4 in which said {111} side walls diverge in a direction away from said substrate surface.
Claim 7
Dependent Claim
21 words
A process according to claim 4 in which said {111} side walls converge in a direction away from said substrate surface.
Claim 8
Dependent Claim
57 words
A process according to any one of claims 1 through 6 in which gallium arsenide or gallium aluminum arsenide is selectively deposited in each of the channels by a vapor phase double decomposition reaction of arsenic, gallium, and, optionally, aluminum compounds at a temperature of from 500 to 800°C from an atmosphere of less than 50 torr.
Claim 9
Dependent Claim
20 words
A process according to claim 7 in which epitaxial deposition is undertaken at a pressure of less than 10 torr.
Claim 10
Dependent Claim
20 words
A process according to claim 7 in which epitaxial deposition is undertaken at a temperature of from 650 to 750°C.
Claim 11
Dependent Claim
52 words
A process according to any one of claims 1 through 9 in which gallium arsenide or gallium aluminum arsenide is selectively deposited epitaxially in said channel by a vapor phase double decomposition reaction of arsenine and at least one of trialkyl gallium and trialkyl aluminum, where alkyl is independently methyl or ethyl.
Claim 12
Dependent Claim
28 words
A process according to any one of claims 1 through 10 in which said substrate adjacent said one major surface exhibits a resistivity of greater than 10⁷ ohm-cm.
Claim 13
Dependent Claim
78 words
A process according to any one of claims 1 through 11 in which said lasing region is comprised of N and P conductivity type cladding regions of aluminum arsenide or gallium aluminum arsenide containing from 10¹⁶ to 10¹⁸ conductivity imparting ions per cubic centimeter and an intervening active layer of gallium arsenide or gallium aluminum arsenide containing less aluminum than either of said cladding regions and less aluminum than at least that portion of said substrate contiguous therewith.
Claim 14
Dependent Claim
25 words
A process according to any one of claims 1 through 12 in which at least one protective layer is formed of silica or silicon nitride.
Claim 15
Dependent Claim
34 words
A process according to any one of claims 1 through 13 in which epitaxial deposition of said lasing region is terminated within less than a micrometer of said one major surface of the substrate.
Claim 16
Dependent Claim
29 words
A process according to claim 14 in which epitaxial deposition of said lasing regions is terminated within less than 3000 Angstroms of said one major surface of said substrate.
Claim 17
Dependent Claim
32 words
A process according to any one of claims 1 through 15 in which said surface layer is formed of a conductivity type opposite that of said substrate, thereby forming a junction therewith.
Claim 18
Dependent Claim
18 words
a process according to claim 16 in which a Schottky barrier layer is deposited on said surface layer.
Claim 19
Dependent Claim
29 words
A process according to any one claims 1 through 16 in which said surface layer is provided with source, drain, and gate electrode to form a field effect transistor.
Claim 20
Dependent Claim
197 words
A semiconductor device comprised of a substrate having a major surface, a laterally restricted lasing region comprising superimposed P and N conductivity type cladding layers, an active layer therebetween, and a capping layer adjacent said major surface having greater than 10¹⁹ conductivity imparting ions per cm³, a semiconductor surface layer laterally offset from said lasing region having a conductivity imparting ion concentation less than that of said capping layer, said substrate and said layers together forming a monocrystalline III-V compound structure, wherein the group V ions are arsenic and the group III ions are at least one of gallium and aluminum, and conductive means at said compound structure surface for providing a conduction path between said surface layer and said capping layer, characterized in that said substrate forms with said capping layer and said surface layer a planar surface of said monocrystalline III-V compound structure, said conductive means is located on said planar surface, and said substrate comprises monocrystalline gallium aluminum arsenide of a single conductivity type having a resistivity of greater than 10 ⁵ ohm-cm isolating said surface layer from said lasing region and providing positive index wave guiding at its interface with said active layer.
Claim 21
Dependent Claim
197 words
A semiconductor device comprised of a substrate having a major surface, a laterally restricted lasing region comprising superimposed P and N conductivity type cladding layers, an active layer therebetween, and a capping layer adjacent said major surface having greater than 10¹⁹ conductivity imparting ions per cm³, a semiconductor surface layer laterally offset from said lasing region having a conductivity imparting ion concentation less than that of said capping layer, said substrate and said layers together forming a monocrystalline III-V compound structure, wherein the group V ions are arsenic and the group III ions are at least one of gallium and aluminum, and conductive means at said compound structure surface for providing a conduction path between said surface layer and said capping layer, characterized in that said substrate forms with said capping layer and said surface layer a planar surface of said monocrystalline III-V compound structure, said conductive means is located on said planar surface, and said substrate comprises monocrystalline gallium aluminum arsenide of a single conductivity type having a resistivity of greater than 10 ⁵ ohm-cm isolating said surface layer from said lasing region and providing positive index wave guiding at its interface with said active layer.
Claim 22
Dependent Claim
38 words
A semiconductor device according to claim 19 wherein said substrate includes a more conductive portion spaced from said one major surface and at least one of said lasing regions extends into said substrate to said more conductive portion.
Claim 23
Dependent Claim
31 words
A semiconductor device according to claim 19 or 20 in which said substrate presents a {100} crystal face and a longitudinal axis of each channel is formed along a <110> vector.
Claim 24
Dependent Claim
25 words
A semiconductor device according to claim 21 in which said lasing region has side walls which intersect said {100} crystal face at a 55° angle.
Claim 25
Dependent Claim
22 words
A semiconductor device according to claim 22 in which said side walls diverge in a direction away from said {100} crystal face.
Claim 26
Dependent Claim
22 words
A semiconductor device according to claim 22 in which said side walls converge in a direction away from said {100} crystal face.
Claim 27
Dependent Claim
35 words
A semiconductor device according to any one of claims 19 through 24 in which a portion of said substrate separating said lasing region and said surface layer exhibits a resistivity of greater than 10⁷ ohm-cm.
Claim 28
Dependent Claim
76 words
A semiconductor device according to any one of claims 19 through 25 in which said lasing region is comprised of N and P conductivity type cladding regions of aluminum arsenide or gallium aluminum arsenide containing from 10¹⁶ to 10¹⁹ con ductivity imparting ions per cubic centimeter and an intervening active layer of gallium arsenide or gallium aluminum arsenide containing less aluminum than either of said cladding regions and less aluminum than contiguous portions of said substrate.
Claim 29
Dependent Claim
25 words
A semiconductor device according to any one of claims 19 through 16 in said III-V compound structure exhibits surface relief of less than 1 micrometer.
Claim 30
Dependent Claim
26 words
A semiconductor device according to any one of laims 10 through 26 in which said III-V compound structure exhibits surface relief of less than 3000 Angstroms.
Claim 31
Dependent Claim
26 words
A semiconductor device according to any one of laims 10 through 26 in which said III-V compound structure exhibits surface relief of less than 3000 Angstroms.
Claim 32
Dependent Claim
234 words
A semiconductor device according to claim 19 wherein said substrate includes a first portion having a conductivity imparting ion concentration of from 1 to 3 X 10¹⁸ ions per cubic centimeter and a second, epitaxially grown isolating portion comprised of gallium aluminum arsenide containing from 30 to 60 mole percent aluminum having a resistivity of greater than 10⁷ ohm-cm, said isolating substrate portion forming one major surface of the substrate, and said lasing region includes in sequence a first gallium arsenide layer having a first conductive type ion concentration of from 10¹⁷ to 5 X 10¹⁸ ions per cc, a first cladding layer comprised of aluminum arsenide or gallium aluminum arsenide containing at least 90 mole percent aluminum having a first conductivity type ion concentration of from 10¹⁶ to 10¹⁸ ions per cc, an active layer comprised of gallium arsenide having a substantially lower conductivity imparting ion concentration than the first cladding layer, a second cladding layer comprised of aluminum arsenide or gallium aluminum arsenide containing at least 90 mole percent aluminum having a second conductivity type ion concentration of from 10¹⁶ to 10¹⁸ ions per cc, and a surface gallium arsenide layer having a second conductivity type ion concentration of greater than 10¹⁹ ions per cc, said surface gallium arsenide layer lying at or beneath the one major surface by a distance of less than 3000 Angstroms to form a planar surface therewith.
Claim 33
Dependent Claim
27 words
A semiconductor according to claim 29 in which said surface layer has a dopant concentration in the range of from from 10¹⁴ to 10¹⁷ ions per cm³.
References Cited (Backward Citations)
No citation records indexed.
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