USH95H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heterojunction D- (or A+) millimeter and submillimeter wave detector
Assignee: United States Department of the Navy
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Filing: 1985-11-27
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Granted: 1986-07-01
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Expires: 2005-11-27
Abstract
Abstract A solid state detector for use in detecting submillimeter and millimeter wave radiation. The solid state detector comprises a semiconductor superlattice of alternating thin epitaxial layers of GaAs and AlGaAs doped with impurities having the same conductivity type. Because of the transfer of charge carriers in order to obtain thermal equilibrium, the charge carriers in the higher energy doped layer transfer to the adjacent lower energy doped layer and form a predetermined number of either D - or A + centers in this layer. This D - or A + center formation is obtained without the use of an optical bias. The ionization energy for these D - or A + centers is small enough that photons from millimeter or submillimeter wave radiation is sufficient to ionize these carriers and yield a measurable conductivity in the device.
Inventors
- 👤 Benjamin V. Shanabrook
- 👤 William J. Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:09
CPC Classifications
B; B82; B82Y; B82Y20/00; H; H10; H10F; H10F77/00; H10F77/10; H10F77/14; H10F77/146
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
119 words
A solid state detector for submillimeter and millimeter wave detection, which utilize no optical bias, comprising: a semiconductor superlattice comprising alternating thin epitaxial layers of at least two different semiconductor materials, with said at least two different alternating materials having different bandgaps with the intrinsic bandgap difference therebetween being greater than KT, where K is the Boltzmann constant and T is the detector operating temperature, wherein said at least two semiconductor materials are doped with dopant molecules of the same conductivity type, such that some carriers resulting from said doping transfer from one of said doped thin epitaxial layers to an adjacent doped thin epitaxial layer and become weakly bound to a dopant molecule in said adjacent doped layer.
Claim 2
Dependent Claim
119 words
A solid state detector for submillimeter and millimeter wave detection, which utilize no optical bias, comprising: a semiconductor superlattice comprising alternating thin epitaxial layers of at least two different semiconductor materials, with said at least two different alternating materials having different bandgaps with the intrinsic bandgap difference therebetween being greater than KT, where K is the Boltzmann constant and T is the detector operating temperature, wherein said at least two semiconductor materials are doped with dopant molecules of the same conductivity type, such that some carriers resulting from said doping transfer from one of said doped thin epitaxial layers to an adjacent doped thin epitaxial layer and become weakly bound to a dopant molecule in said adjacent doped layer.
Claim 3
Dependent Claim
16 words
A detector as defined in claim 1, wherein said semiconductor superlattice is a Type I superlattice.
Claim 4
Dependent Claim
19 words
A detector as defined in claim 2 wherein said at least two different semiconductor materials are GaAs and AlGaAs.
Claim 5
Dependent Claim
16 words
A detector as defined in claim 3, wherein said dopant molecules are an n conductivity type.
Claim 6
Dependent Claim
16 words
A detector as defined in claim 3, wherein said dopant molecules are a p conductivity type.
Claim 7
Dependent Claim
19 words
A detector as defined in claim 2, wherein said thin epitaxial layers are in the range of 25-300 angstroms.
Claim 8
Independent Claim
171 words
A method for detecting millimeter, submillimeter, and infrared waves, comprising the steps of: disposing a semiconductor superlattice with a surface in a position to have millimeter, submillimeter, or infrared wave photons impinge on said superlattice surface, said superlattice comprising alternating thin epitaxial layers of at least two different semiconductor materials, with the at least two different materials having different intrinsic bandgaps, with the bandgap difference therebetween being greater than KT, where K is the Boltzmann constant and T is the detector operating temperature, wherein said at least two semiconductor materials are doped with neutral dopant molecules of the same conductivity type, such that some carriers resulting from said doping transfer from one of said doped thin epitaxial layers to an adjacent doped thin epitaxial layer and become weakly bound to a neutral dopant molecule in said adjacent doped layer; and detecting an increase in conductivity in said semiconductor superlattice when millimeter, submillimeter, or infrared wave photons impinge on said semiconductor superlattice and remove the weakly bound carries from said dopant molecules.
Claim 9
Independent Claim
171 words
A method for detecting millimeter, submillimeter, and infrared waves, comprising the steps of: disposing a semiconductor superlattice with a surface in a position to have millimeter, submillimeter, or infrared wave photons impinge on said superlattice surface, said superlattice comprising alternating thin epitaxial layers of at least two different semiconductor materials, with the at least two different materials having different intrinsic bandgaps, with the bandgap difference therebetween being greater than KT, where K is the Boltzmann constant and T is the detector operating temperature, wherein said at least two semiconductor materials are doped with neutral dopant molecules of the same conductivity type, such that some carriers resulting from said doping transfer from one of said doped thin epitaxial layers to an adjacent doped thin epitaxial layer and become weakly bound to a neutral dopant molecule in said adjacent doped layer; and detecting an increase in conductivity in said semiconductor superlattice when millimeter, submillimeter, or infrared wave photons impinge on said semiconductor superlattice and remove the weakly bound carries from said dopant molecules.
Claim 10
Dependent Claim
21 words
A method as defined in claim 7, wherein said superlattice disposing step comprises the step of disposing a Type I superlattice.
Claim 11
Dependent Claim
34 words
A method as defined in claim 8, wherein said superlattice disposing step comprises the step of disposing a superlattice with alternating layers of GaAs and AlGaAs with a layer thickness range of 25-300 angstroms.
Claim 12
Independent Claim
131 words
A method for detecting millimeter, submillimeter, and infrared waves with no optical bias, comprising the steps of: disposing a D - semiconductor superlattice with a surface and with no optical biasing or pre-biasing in a position to have millimeter, submillimeter, and infrared wave photons impinge on said superlattice surface, said superlattice comprising alternating thin epitaxial layers of two different semiconductor materials, with said two different semiconductor materials having different bandgaps, with the bandgap difference therebetween being greater then KT, where K is the Boltzmann constant and T is the detector operating temperature, wherein at least alternating ones of said thin semiconductor layers are D - center layers; and detecting an increase in conductivity in said semiconductor superlattice when millimeter, submillimeter, or infrared wave photons impinge on said D - semiconductor superlattice.
Claim 13
Independent Claim
131 words
A method for detecting millimeter, submillimeter, and infrared waves with no optical bias, comprising the steps of: disposing a D - semiconductor superlattice with a surface and with no optical biasing or pre-biasing in a position to have millimeter, submillimeter, and infrared wave photons impinge on said superlattice surface, said superlattice comprising alternating thin epitaxial layers of two different semiconductor materials, with said two different semiconductor materials having different bandgaps, with the bandgap difference therebetween being greater then KT, where K is the Boltzmann constant and T is the detector operating temperature, wherein at least alternating ones of said thin semiconductor layers are D - center layers; and detecting an increase in conductivity in said semiconductor superlattice when millimeter, submillimeter, or infrared wave photons impinge on said D - semiconductor superlattice.
Claim 14
Dependent Claim
21 words
A method as defined in claim 10, wherein said superlattice disposing step comprises the step of disposing a Type I superlattice.
Claim 15
Dependent Claim
34 words
A method as defined in claim 11, wherein said superlattice disposing step comprises the step of disposing a superlattice with alternating layers of GaAs and AlGaAs with a layer thickness range of 25-300 angstroms.
Claim 16
Independent Claim
131 words
A method for detecting millimeter, submillimeter, and infrared waves with no optical bias, comprising the steps of: disposing an A + semiconductor superlattice with a surface and with no optical biasing or pre-biasing in a position to have millimeter, submillimeter, and infrared wave photons impinge on said superlattice surface, said superlattice comprising alternating thin epitaxial layers of two different semiconductor materials, with said two different semiconductor materials having different bandgaps, with the bandgap difference therebetween being greater than KT, where K is the Boltzmann constant and T is the detector operating temperature, wherein at least alternating ones of said thin semiconductor layers are A + center layers; and detecting an increase in conductivity in said semiconductor superlattice when millimeter, submillimeter, or infrared wave photons impinge on said A + semiconductor superlattice.
Claim 17
Independent Claim
131 words
A method for detecting millimeter, submillimeter, and infrared waves with no optical bias, comprising the steps of: disposing an A + semiconductor superlattice with a surface and with no optical biasing or pre-biasing in a position to have millimeter, submillimeter, and infrared wave photons impinge on said superlattice surface, said superlattice comprising alternating thin epitaxial layers of two different semiconductor materials, with said two different semiconductor materials having different bandgaps, with the bandgap difference therebetween being greater than KT, where K is the Boltzmann constant and T is the detector operating temperature, wherein at least alternating ones of said thin semiconductor layers are A + center layers; and detecting an increase in conductivity in said semiconductor superlattice when millimeter, submillimeter, or infrared wave photons impinge on said A + semiconductor superlattice.
Claim 18
Dependent Claim
21 words
A method as defined in claim 13, wherein said superlattice disposing step comprises the step of disposing a Type I superlattice.
Claim 19
Dependent Claim
34 words
A method as defined in claim 14, wherein said superlattice disposing step comprises the step of disposing a superlattice with alternating layers of GaAs and AlGaAs with a layer thickness range of 25-300 angstroms.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-30 | 1989-12-30 | 1990-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-30 | 1993-12-30 | 1994-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-30 | 1997-12-30 | 1998-07-01 | $7700.00 | Window Closed / Lapsed |