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US5389797A Expired / Lapsed US ⏱️ 0.0 years remaining

Photodetector with absorbing region having resonant periodic absorption between reflectors

Assignee: United States Department of Energy
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Filing: 1993-02-24
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Granted: 1995-02-14
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Expires: 2013-02-24
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Abstract

Abstract A photodetector that is responsive to a wavelength or wavelengths of interest which have heretofore been unrealized. The photodetector includes a resonant cavity structure bounded by first and second reflectors, the resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves therein. The photodetector further includes a radiation absorbing region disposed within the resonant cavity structure, the radiation absorbing region including a plurality of radiation absorbing layers spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves. Each of radiation absorbing layers is spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced. The radiation absorbing layers may be either bulk layers or quantum wells includes a plurality of layers, each of which is comprised of a strained layer of InGaAs. Individual ones of the InGaAs layers are spaced apart from one another by a GaAs barrier layer.

Inventors

  • 👤 Robert P. Bryan
  • 👤 Gregory R. Olbright
  • 👤 Thomas M. Brennan
  • 👤 Jeffrey Y. Tsao

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 16:35
CPC Classifications
H; H10; H10F; H10F77/00; H10F77/10; H10F77/14; H10F77/40; H10F77/413

Claims Analysis

Total Claims: 34
Claim 1
Independent Claim 125 words
A photodetector responsive to a wavelength or wavelengths of interest, comprising: (a) a resonant cavity structure, said resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves; and (b) a photodetector disposed within said resonant cavity structure, said photodetector having a radiation absorbing region comprising a plurality of quantum wells, said quantum wells spaced apart from one another by a distance substantially equal to a distance between antinodes of the standing waves, each of said quantum wells further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced through resonant periodic absorption.
Claim 2
Dependent Claim 125 words
A photodetector responsive to a wavelength or wavelengths of interest, comprising: (a) a resonant cavity structure, said resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves; and (b) a photodetector disposed within said resonant cavity structure, said photodetector having a radiation absorbing region comprising a plurality of quantum wells, said quantum wells spaced apart from one another by a distance substantially equal to a distance between antinodes of the standing waves, each of said quantum wells further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced through resonant periodic absorption.
Claim 3
Dependent Claim 27 words
A photodetector as set forth in claim 1 wherein said first and said second reflector means are from a group consisting of metals, insulators, dielectrics, and semiconductors.
Claim 4
Dependent Claim 21 words
A photodetector as set forth in claim 2 wherein said first and said second reflector means are semiconductor distributed Bragg reflectors.
Claim 5
Dependent Claim 15 words
A photodetector as set forth in claim 3 wherein said distributed Bragg reflectors are asymmetric.
Claim 6
Dependent Claim 37 words
A photodetector as set forth in claim 1, wherein said photodetector is from a group consisting of PN photodiode, PIN photodiode, avalanche photodiode, heterojunction phototransistor, a double heterojunction phototransistor, a heterojunction bipolar transistor, and a MSM detector.
Claim 7
Dependent Claim 50 words
A photodetector as set forth in claim 1, wherein said radiation absorbing region comprises a plurality of groups of quantum wells and where there is more than one of said group, each one of said quantum wells within a group being spaced apart from one another by a spacer layer.
Claim 8
Dependent Claim 24 words
A photodetector as set forth in claim 6, wherein each of said quantum wells includes a plurality of layers, and said layers are strained.
Claim 9
Dependent Claim 24 words
A photodetector as set forth in claim 6, wherein each of said quantum wells includes a plurality of layers, and said layers are unstrained.
Claim 10
Dependent Claim 45 words
A photodetector as set forth in claim 6, wherein each of said quantum wells includes a plurality of layers each of which is comprised of strained InGaAs, individual ones of said strained InGaAs layers being spaced apart from one another by a GaAs barrier layer.
Claim 11
Dependent Claim 123 words
A photodetector-responsive to a wavelength or wavelengths of interest, comprising: (a) a resonant cavity structure, said resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves; and (b) a radiation absorbing region disposed within said resonant cavity structure, said radiation absorbing region comprising one or more bulk layers, said bulk layers spaced apart from one another by a distance substantially equal to a distance between antinodes of the standing waves, each of said bulk layers further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced through resonant periodic absorption.
Claim 12
Dependent Claim 123 words
A photodetector-responsive to a wavelength or wavelengths of interest, comprising: (a) a resonant cavity structure, said resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves; and (b) a radiation absorbing region disposed within said resonant cavity structure, said radiation absorbing region comprising one or more bulk layers, said bulk layers spaced apart from one another by a distance substantially equal to a distance between antinodes of the standing waves, each of said bulk layers further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced through resonant periodic absorption.
Claim 13
Dependent Claim 27 words
A photodetector as set forth in claim 10, wherein said first and said second reflector means are from a group consisting of metals, insulators, dielectrics, and semiconductors.
Claim 14
Dependent Claim 21 words
A photodetector as set forth in claim 11, wherein said first and said second reflector means are semiconductor distributed Bragg reflectors.
Claim 15
Dependent Claim 15 words
A photodetector as set forth in claim 12, wherein said distributed Bragg reflectors are asymmetric.
Claim 16
Dependent Claim 37 words
A photodetector as set forth in claim 10, wherein said photodetector is from a group consisting of PN photodiode, PIN photodiode, avalanche photodiode, heterojunction phototransistor, a double heterojunction phototransistor, a heterojunction bipolar transistor, and a MSM detector.
Claim 17
Dependent Claim 218 words
A phototransistor, comprising: (a) a substrate; (b) a first reflector means disposed over said substrate; (c) a sub-collector layer disposed over said first reflector means, said sub-collector layer having a first type of electrical conductivity; (d) a radiation absorbing collector region disposed over said sub-collector layer, said radiation absorbing collector region including a plurality of quantum wells, said radiation absorbing collector region having said first type of electrical conductivity; (e) a base layer disposed over said radiation absorbing collector region, said base layer having a second type of electrical conductivity; (f) an emitter layer disposed over said base layer, said emitter layer having said first type of electrical conductivity; and (g) a second reflector means disposed over said emitter layer and forming, with said first reflector means, a resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at a wavelength or wavelengths of interest for containing a plurality of standing waves; wherein each of said quantum wells are spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves, each of said plurality of quantum wells further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced.
Claim 18
Dependent Claim 218 words
A phototransistor, comprising: (a) a substrate; (b) a first reflector means disposed over said substrate; (c) a sub-collector layer disposed over said first reflector means, said sub-collector layer having a first type of electrical conductivity; (d) a radiation absorbing collector region disposed over said sub-collector layer, said radiation absorbing collector region including a plurality of quantum wells, said radiation absorbing collector region having said first type of electrical conductivity; (e) a base layer disposed over said radiation absorbing collector region, said base layer having a second type of electrical conductivity; (f) an emitter layer disposed over said base layer, said emitter layer having said first type of electrical conductivity; and (g) a second reflector means disposed over said emitter layer and forming, with said first reflector means, a resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at a wavelength or wavelengths of interest for containing a plurality of standing waves; wherein each of said quantum wells are spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves, each of said plurality of quantum wells further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced.
Claim 19
Dependent Claim 216 words
A phototransistor, comprising: (a) a substrate; (b) a first reflector means disposed over said substrate; (c) a sub-collector layer disposed over said first reflector means, said sub-collector layer having a first type of electrical conductivity; (d) a collector region disposed over said sub-collector layer, said collector region having said first type of electrical conductivity; (e) a radiation absorbing base layer disposed over said collector region, said radiation absorbing base layer including a plurality of quantum wells, said radiation absorbing base layer having a second type of electrical conductivity; (f) an emitter layer disposed over said base layer, said emitter layer having said first type of electrical conductivity; and (g) a second reflector means disposed over said emitter layer and forming, with said first reflector means, a resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at a wavelength or wavelengths of interest for containing a plurality of standing waves; wherein each of said quantum wells are spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves, each of said plurality of quantum wells further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced.
Claim 20
Dependent Claim 216 words
A phototransistor, comprising: (a) a substrate; (b) a first reflector means disposed over said substrate; (c) a sub-collector layer disposed over said first reflector means, said sub-collector layer having a first type of electrical conductivity; (d) a collector region disposed over said sub-collector layer, said collector region having said first type of electrical conductivity; (e) a radiation absorbing base layer disposed over said collector region, said radiation absorbing base layer including a plurality of quantum wells, said radiation absorbing base layer having a second type of electrical conductivity; (f) an emitter layer disposed over said base layer, said emitter layer having said first type of electrical conductivity; and (g) a second reflector means disposed over said emitter layer and forming, with said first reflector means, a resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at a wavelength or wavelengths of interest for containing a plurality of standing waves; wherein each of said quantum wells are spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves, each of said plurality of quantum wells further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced.
Claim 21
Dependent Claim 27 words
A phototransistor as set forth in claim 15, wherein said first type of electrical conductivity is n-type, and wherein said second type of electrical conductivity is p-type.
Claim 22
Dependent Claim 27 words
A phototransistor as set forth in claim 15, wherein said first type of electrical conductivity is p-type, and wherein said second type of electrical conductivity is n-type.
Claim 23
Dependent Claim 37 words
A phototransistor as set forth in claim 15, wherein each of said quantum wells is comprised of a group of quantum wells, individual ones of said groups being spaced apart from one another by a barrier layer.
Claim 24
Dependent Claim 43 words
A phototransistor as set forth in claim 15, wherein each of said quantum wells includes a plurality of layers each of which is comprised of InGaAs, individual ones of said InGaAs layers being spaced apart from one another by a GaAs barrier layer.
Claim 25
Dependent Claim 65 words
A phototransistor as set forth in claim 20, wherein each of said quantum wells is comprised of a plurality of layers of In 0 .12 Ga 0 .88 As, each of said layers being approximately 80 Å thick, and wherein individual ones of said plurality of layers are spaced apart from one another by a GaAs barrier layer having a thickness of approximately 100 Å.
Claim 26
Dependent Claim 21 words
A phototransistor as set forth in claim 15, wherein each of said reflector means is comprised of a distributed Bragg reflector.
Claim 27
Dependent Claim 19 words
A phototransistor as set forth in claim 15, wherein a plurality of said phototransistors are provided on said substrate.
Claim 28
Dependent Claim 29 words
A phototransistor as set forth in claim 15, wherein said wavelength or wavelengths of interest are within a range of wavelengths between approximately 900 nanometers and approximately one micrometer.
Claim 29
Dependent Claim 37 words
A phototransistor as set forth in claim 15, and further including an emitter contact disposed over said second reflector means, said emitter contact having an aperture made therein for admitting incident radiation into said resonant cavity structure.
Claim 30
Dependent Claim 217 words
A phototransistor, comprising: (a) a substrate; (b) a first reflector means disposed over said substrate; (c) an emitter layer disposed over said first reflector means, said emitter layer having said first type of electrical conductivity; (d) a base layer disposed over said emitter layer, said base layer having a second type of electrical conductivity; (e) a radiation absorbing collector region disposed over said base layer, said radiation absorbing collector region including a plurality of quantum wells, said radiation absorbing collector region having said first type of electrical conductivity; (f) a sub-collector layer disposed over said radiation absorbing collector region, said sub-collector layer having a first type of electrical conductivity; (g) a second reflector means disposed over said sub-collector layer and forming, with said first reflector means, a resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at a wavelength or wavelengths of interest for containing a plurality of standing waves; wherein each of said quantum wells are spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves, each of said plurality of quantum wells further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced.
Claim 31
Dependent Claim 217 words
A phototransistor, comprising: (a) a substrate; (b) a first reflector means disposed over said substrate; (c) an emitter layer disposed over said first reflector means, said emitter layer having said first type of electrical conductivity; (d) a base layer disposed over said emitter layer, said base layer having a second type of electrical conductivity; (e) a radiation absorbing collector region disposed over said base layer, said radiation absorbing collector region including a plurality of quantum wells, said radiation absorbing collector region having said first type of electrical conductivity; (f) a sub-collector layer disposed over said radiation absorbing collector region, said sub-collector layer having a first type of electrical conductivity; (g) a second reflector means disposed over said sub-collector layer and forming, with said first reflector means, a resonant cavity structure bounded by first and second reflector means, said resonant cavity structure being resonant at a wavelength or wavelengths of interest for containing a plurality of standing waves; wherein each of said quantum wells are spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves, each of said plurality of quantum wells further being spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced.
Claim 32
Dependent Claim 65 words
A phototransistor as set forth in claim 26, wherein each of said quantum wells includes a plurality of layers each of which is comprised of InGaAs, individual ones of said InGaAs layers being spaced apart from one another by a GaAs barrier layer, and wherein said wavelength or wavelengths of interest are within a range of wavelengths between approximately 900 nm and approximately one micrometer.
Claim 33
Dependent Claim 65 words
A phototransistor as set forth in claim 26, wherein each of said quantum wells is comprised of a plurality of layers of In 0 .12 Ga 0 .88 As, each of said layers being approximately 80 Å thick, and wherein individual ones of said plurality of layers are spaced apart from one another by a GaAs barrier layer having a thickness of approximately 100 Å.
Claim 34
Dependent Claim 39 words
A phototransistor as set forth in claim 26, and further including an emitter contact disposed over a bottom surface of said substrate, said emitter contact having an aperture made therein for admitting incident radiation into said resonant cavity structure.

References Cited (Backward Citations)

US4943970A Cited
US4949350A Cited
JPH03109779A Cited
US5229627A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-02-13 1998-08-15 1999-02-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-02-13 2002-08-15 2003-02-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-02-13 2006-08-15 2007-02-14 $7700.00 Window Closed / Lapsed

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