US4839706A
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Avalanche photodetector
Assignee: Polaroid Corp
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Filing: 1986-08-07
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Granted: 1989-06-13
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Expires: 2006-08-07
Abstract
Abstract A low noise doped quantum well avalanche photodector (APD) having repeated superlattice units. Where the majority carriers are electrons, each unit is formed from p + -n + layers of a first material having a first ionization threshold, a near intrinsic layer of a second material having a smaller ionization threshold, and a near intrinsic layer of the first material. Such an APD can be fabricated in the GaAs/AlGaAs material system.
Inventors
- 👤 Kevin F. Brennan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:48
CPC Classifications
B; B82; B82Y; B82Y20/00; H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/225; H10F30/2255; H10F77/00; H10F77/10; H10F77/14; H10F77/146
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
66 words
In an avalanche photodetector device comprising: at least one unit which includes the following contiguous layers in sequence: a p + doped layer of a first material having a first ionization threshold, an n + layer of the first material, a substantially intrinsic layer of a second material having a smaller ionization threshold than the first material, and a substantially intrinsic layer of the first material.
Claim 2
Dependent Claim
66 words
In an avalanche photodetector device comprising: at least one unit which includes the following contiguous layers in sequence: a p + doped layer of a first material having a first ionization threshold, an n + layer of the first material, a substantially intrinsic layer of a second material having a smaller ionization threshold than the first material, and a substantially intrinsic layer of the first material.
Claim 3
Dependent Claim
111 words
In the device of claim 1 wherein: the doping level of the p + layer and of the n + layer is each greater than 2.0×10 18 cm --3 , the width of the p + layer and of the n + layer is each in the approximate range of 95 to 300 angstroms, the width of the substantially intrinsic layer of the second material is in the approximate range of 180 to 300 angstroms, the width of the substantially intrinsic layer of the first material is in the approximate range of 200 to 500 angstroms, and the first material is GaAs and the second material is an alloy of GaAs.
Claim 4
Dependent Claim
27 words
In the device of claim 2 wherein the alloy of AlGaAs is Al x Ga 1-x As, x being in the approximate range between 0.4 to 0.45.
Claim 5
Dependent Claim
70 words
A device in accordance with claim 3 which further comprises a highly p doped semiconductor layer, contiguous with the p + layer of the first unit of said at least one unit, a highly n doped semiconductor layer contiguous with the substantially intrinsic layer of the first material of the last of the at least one unit, and electrodes ohmerically contacted to the highly doped p and n semiconductor layers.
Claim 6
Dependent Claim
47 words
The device of claim 4 which further comprises a source of voltage for reverse biasing the device electrodes to generate an electric field in the p + layer and in the n + layer having an average value in the approximate range of 100 to 200 kV/cm.
Claim 7
Dependent Claim
66 words
In an avalanche photodetector device comprising: at least one unit which includes the following contiguous layers in sequence: a substantially intrinsic layer of a first material having a first ionization potential, a substantially intrinsic layer of a second material having a smaller ionization threshold than the first material, an n + layer of the first material, and a p + doped layer of the first material.
Claim 8
Dependent Claim
66 words
In an avalanche photodetector device comprising: at least one unit which includes the following contiguous layers in sequence: a substantially intrinsic layer of a first material having a first ionization potential, a substantially intrinsic layer of a second material having a smaller ionization threshold than the first material, an n + layer of the first material, and a p + doped layer of the first material.
Claim 9
Dependent Claim
109 words
In the device of claim 6 wherein: the doping level of the p + layer and of the n + layer is each greater than 2.0×cm -3 , the width of the substantially intrinsic layer of the first material is in the approximate range of 200 to 500 angstroms, the width of the substantially intrinsic layer of the second material is in the approximate range of 180 to 300 angstroms, the width of the p + layer and of the n + layer is each in the approximate range of 95 to 300 angstroms, and the first material is AlGaAs and the second material is an alloy of GaAs.
Claim 10
Dependent Claim
27 words
In the device of claim 7 wherein the alloy of AlGaAs is Al x Ga 1-x As, x being in the approximate range between 0.4 to 0.45.
Claim 11
Dependent Claim
71 words
A device in accordance with claim 8 which further comprises a highly p doped semiconductor layer contiguous with the p + layer of the first unit of said at least one unit, a highly n doped semiconductor layer contiguous with the substantially intrinsic layer of the first material of the last unit of said at least one unit, and electrodes ohmically contacted to the highly doped p and n semiconductor layers.
Claim 12
Dependent Claim
46 words
The device of claim 9 which further comprises a source of voltage for reverse biasing the electrodes to generate an electric field in the p + layer and in the n + layer having an average value in the approximate range of 100 to 200 kV/cm.
Claim 13
Dependent Claim
24 words
In the device of claim 1 wherein the first material is an alloy of AlInAs and the second material is an alloy of GaInAs.
Claim 14
Dependent Claim
24 words
In the device of claim 6 wherein the first material is an alloy of AlInAs and the second material is an alloy of GaInAs.
Claim 15
Dependent Claim
21 words
In the device of claim 1 wherein the first material is an alloy of InGaAs and the second material is InP.
Claim 16
Dependent Claim
21 words
In the device of claim 6 wherein the first material is an alloy of InGaAs and the second material is InP.
Claim 17
Dependent Claim
21 words
In the device of claim l wherein the first material is an alloy of InGaAsP and the second material is InP.
Claim 18
Dependent Claim
21 words
In the device of claim 6 wherein the first material is an alloy of InGaAs and the second material is InP.
Claim 19
Dependent Claim
73 words
In an avalanche photodetector device wherein the majority carriers are holes comprising: at least one unit which includes the following contiguous layers in sequence: a first substantially intrinsic layer of a first material having a first ionization potential, a substantially intrinsic layer of a second material having a smaller ionization threshold than the first material. a p + layer of the first material, and an n + doped layer of a first material.
Claim 20
Dependent Claim
73 words
In an avalanche photodetector device wherein the majority carriers are holes comprising: at least one unit which includes the following contiguous layers in sequence: a first substantially intrinsic layer of a first material having a first ionization potential, a substantially intrinsic layer of a second material having a smaller ionization threshold than the first material. a p + layer of the first material, and an n + doped layer of a first material.
Claim 21
Dependent Claim
21 words
In the device of claim 17 wherein the first material is an alloy of InGaAs and the second material is InP.
Claim 22
Dependent Claim
21 words
In the device of claim 17 wherein the first material is an alloy of InGaAsP and the second material is InP.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |