US4473835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Long wavelength avalanche photodetector
Assignee: Nokia Bell Labs
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Filing: 1981-06-19
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Granted: 1984-09-25
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Expires: 2001-06-19
Abstract
Abstract An avalanche photodetector useful at wavelengths as long as 1.7 microns with low noise is achieved. The crystal used includes successive layers of p-type indium phosphide, n-type indium phosphide, and n-type indium gallium arsenide. An appropriate total of fixed charges in the n-type indium phosphide and a graded bandgap heterointerface region are important for the improved results.
Inventors
- 👤 Stephen R. Forrest
- 👤 Ock-Ky Kim
- 👤 Richard G. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:34
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/225; H10F30/2255
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
121 words
A semiconductive device useful as an avalanche photodetector comprising means forming connections for applying operating voltages to such device and a semiconductive crystal electrically between such means, such crystal comprising in succession a first region of p-type indium phosphide, a second region contiguous to the first region of n-type indium phosphide, a third region contiguous with the second region of n-type indium gallium arsenide phosphide, and a fourth region contiguous with the third region of n-type indium gallium arsenide, the n-type indium phosphide region having a fixed charge in the range to minimize tunneling in the fourth region and to allow for avalanching in the second region, and the third region being of a thickness and composition to reduce storage effects.
Claim 2
Dependent Claim
121 words
A semiconductive device useful as an avalanche photodetector comprising means forming connections for applying operating voltages to such device and a semiconductive crystal electrically between such means, such crystal comprising in succession a first region of p-type indium phosphide, a second region contiguous to the first region of n-type indium phosphide, a third region contiguous with the second region of n-type indium gallium arsenide phosphide, and a fourth region contiguous with the third region of n-type indium gallium arsenide, the n-type indium phosphide region having a fixed charge in the range to minimize tunneling in the fourth region and to allow for avalanching in the second region, and the third region being of a thickness and composition to reduce storage effects.
Claim 3
Dependent Claim
21 words
A device in accordance with claim 1 further characterized in that the third region is at least several hundred Angstroms wide.
Claim 4
Dependent Claim
22 words
A device in accordance with claim 1 further characterized in that the third region is in the range of 500-1000 Angstroms thick.
Claim 5
Dependent Claim
23 words
A device in accordance with claim 1 in which the third region has its composition graded between indium phosphide and indium gallium arsenide.
Claim 6
Dependent Claim
34 words
A device in accordance with claim 4 in which the third region is at least several hundred Angstroms and in which the second and third regions are more lightly doped than the first region.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-25 | 1988-03-26 | 1988-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-25 | 1992-03-26 | 1992-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-25 | 1996-03-26 | 1996-09-25 | $7700.00 | Window Closed / Lapsed |