US5122669A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wideband schottky focal plane array
Assignee: Raytheon Co
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Filing: 1991-03-13
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Granted: 1992-06-16
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Expires: 2011-03-13
Abstract
Abstract A radiation detector includes a silicon substrate (12) having opposing first and second major surfaces, the substrate absorbing visible radiation incident upon the first major surface and passing into the substrate for generating charge carriers therefrom. The detector further includes a silicide layer (16) overlying the second major surface of the substrate, the silicide layer forming a Schottky-barrier junction with the underlying substrate. The silicide layer absorbs IR radiation for generating charge carriers therefrom. The substrate has a resistivity of approximately one thousand ohms per centimeter or greater for enhancing responsivity to visible radiation. A cavity structure (16) overlies the silicide layer and has a reflector (18) optically coupled thereto for reflecting IR radiation that passes through the silicide layer back to the silicide layer. To further enhance responsivity the substrate is thinned and has a thickness within a range of approximately 25 microns to approximately 125 microns.
Inventors
- 👤 James R. Herring
- 👤 James L. Gates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:54
CPC Classifications
H; H10; H10F; H10F39/00; H10F39/80; H10F39/805; H10F39/10; H10F39/12; H10F39/18; H10F39/184; H10F39/199; H10F39/802
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
103 words
A radiation detector comprising: a silicon substrate having opposing first and second major surfaces and a thickness within a range of approximately 25 microns to approximately 125 microns, the substrate absorbing radiation within a first spectral band that is incident upon the first major surface for generating charge carriers therefrom; a layer comprised of silicide disposed upon the second major surface of the substrate, the silicide layer forming a Schottky-barrier junction with the underlying substrate and absorbing radiation within a second spectral band for generating charge carriers therefrom; and wherein the substrate has a resistivity of approximately one thousand ohm centimeters or greater.
Claim 2
Dependent Claim
103 words
A radiation detector comprising: a silicon substrate having opposing first and second major surfaces and a thickness within a range of approximately 25 microns to approximately 125 microns, the substrate absorbing radiation within a first spectral band that is incident upon the first major surface for generating charge carriers therefrom; a layer comprised of silicide disposed upon the second major surface of the substrate, the silicide layer forming a Schottky-barrier junction with the underlying substrate and absorbing radiation within a second spectral band for generating charge carriers therefrom; and wherein the substrate has a resistivity of approximately one thousand ohm centimeters or greater.
Claim 3
Dependent Claim
46 words
A radiation detector as set forth in claim 1 and further comprising a cavity structure overlying the layer and having reflector means optically coupled thereto for reflecting any radiation within the second spectral band that passes through the layer back to the layer for absorption therein.
Claim 4
Dependent Claim
21 words
A radiation detector as set forth in claim 1 and further comprising an antireflection coating disposed over the first major surface.
Claim 5
Dependent Claim
27 words
A radiation detector as set forth in claim 1 and further comprising an ion implanted region within the first major surface, the region forming an ohmic contact.
Claim 6
Dependent Claim
36 words
A radiation detector as set forth in claim 1 wherein the first spectral band includes wavelengths of less than approximately one micron and wherein the second spectral band includes wavelengths of greater than approximately one micron.
Claim 7
Dependent Claim
43 words
A radiation detector as set forth in claim 1 wherein the first spectral band includes wavelengths associated with at least the visible regions of electromagnetic spectrum and wherein the second spectral band includes wavelengths associated with the infrared region of the electromagnetic spectrum.
Claim 8
Dependent Claim
17 words
A radiation detector as set forth in claim 1 wherein the silicide layer is comprised of PtSi.
Claim 9
Dependent Claim
17 words
A radiation detector as set forth in claim 1 wherein the silicide layer is comprised of IrSi.
Claim 10
Dependent Claim
16 words
A radiation detector as set forth in claim 1 wherein the substrate is comprised of germanium.
Claim 11
Dependent Claim
130 words
An array of radiation detectors comprising: a substrate comprised of silicon having opposing first and second major surfaces, the substrate absorbing radiation having a wavelength of less than approximately one micron that is incident upon the first major surface for generating charge carriers therefrom; a layer comprised of silicide overlying the second major surface of the substrate, the silicide layer being differentiated into a plurality of silicide regions each of which forms a Schottky-barrier junction with the underlying substrate, each of the silicide regions absorbing radiation having a wavelength of greater than approximately one micron for generating charge carriers therefrom; and wherein the substrate has a resistivity of at least approximately one thousand ohm centimeters and a thickness of greater than approximately 25 microns and less than approximately 125 microns.
Claim 12
Dependent Claim
130 words
An array of radiation detectors comprising: a substrate comprised of silicon having opposing first and second major surfaces, the substrate absorbing radiation having a wavelength of less than approximately one micron that is incident upon the first major surface for generating charge carriers therefrom; a layer comprised of silicide overlying the second major surface of the substrate, the silicide layer being differentiated into a plurality of silicide regions each of which forms a Schottky-barrier junction with the underlying substrate, each of the silicide regions absorbing radiation having a wavelength of greater than approximately one micron for generating charge carriers therefrom; and wherein the substrate has a resistivity of at least approximately one thousand ohm centimeters and a thickness of greater than approximately 25 microns and less than approximately 125 microns.
Claim 13
Dependent Claim
47 words
An array as set forth in claim 10 and further comprising a plurality of cavity structures overlying the layer and having reflector means optically coupled thereto for reflecting any radiation within the second spectral band that passes through the layer back to the layer for absorption therein.
Claim 14
Dependent Claim
20 words
An array as set forth in claim 10 and further comprising an antireflection coating disposed over the first major surface.
Claim 15
Dependent Claim
24 words
An array as set forth in claim 10 and further comprising an ohmic contact that is ion implanted region within the first major surface.
Claim 16
Dependent Claim
16 words
An array as set forth in claim 10 wherein the silicide layer is comprised of PtSi.
Claim 17
Dependent Claim
16 words
An array as set forth in claim 10 wherein the silicide layer is comprised of IrSi.
Claim 18
Independent Claim
139 words
A method of fabricating an array of radiation detectors, comprising the steps of: providing a substrate comprised of silicon having opposing first and second major surfaces; forming a layer comprised of silicide over the second major surface of the substrate, the step of forming the silicide layer including a step of differentiating the silicide layer into a plurality of silicide regions each of which forms a Schottky-barrier junction with the underlying substrate; and forming a plurality of cavity structures overlying the layer and having reflector means optically coupled thereto for reflecting any radiation that passes through the layer back to the layer; and wherein the step of providing a substrate provides a substrate having a resistivity of approximately one thousand ohm centimeters or greater and a thickness of greater than approximately 25 microns and less than approximately 125 microns.
Claim 19
Independent Claim
139 words
A method of fabricating an array of radiation detectors, comprising the steps of: providing a substrate comprised of silicon having opposing first and second major surfaces; forming a layer comprised of silicide over the second major surface of the substrate, the step of forming the silicide layer including a step of differentiating the silicide layer into a plurality of silicide regions each of which forms a Schottky-barrier junction with the underlying substrate; and forming a plurality of cavity structures overlying the layer and having reflector means optically coupled thereto for reflecting any radiation that passes through the layer back to the layer; and wherein the step of providing a substrate provides a substrate having a resistivity of approximately one thousand ohm centimeters or greater and a thickness of greater than approximately 25 microns and less than approximately 125 microns.
Claim 20
Dependent Claim
23 words
A method as set forth in claim 16 and further comprising a step of forming an antireflection coating over the first major surface.
Claim 21
Dependent Claim
30 words
A method as set forth in claim 16 and further comprising a step of ion implanting the first major surface with a dopant species selected for forming an ohmic contact.
Claim 22
Dependent Claim
23 words
A method as set forth in claim 16 wherein the step of forming a layer forms a layer comprised of PtSi or IrSi.
References Cited (Backward Citations)
US3071057A
Cited
US4536658A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |