US4739385A
Expired / Lapsed
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Modulation-doped photodetector
Assignee: Nokia Bell Labs
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Filing: 1987-01-12
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Granted: 1988-04-19
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Expires: 2007-01-12
Abstract
Abstract A modulation-doped field effect photodetector has a fast response time.
Inventors
- 👤 Clyde G. Bethea
- 👤 Chung Y. Chen
- 👤 Alfred Y. Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:56
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/28; H10F30/283; H10F30/2843
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
A photodetector device, said device comprising a first semiconductor layer which comprises a first semiconductor material having a first bandgap; a second semiconductor layer which comprises a second semiconductor material having a second bandgap and a first conductivity type, and said second bandgap being greater than said first bandgap, whereby a two-dimensional electron gas is formed in said first layer; said device comprising source, gate, and drain electrodes on said second semiconductor layer; and the spacing between said gate and drain electrodes being in the range from 8 μm to 100 μm.
Claim 2
Dependent Claim
92 words
A photodetector device, said device comprising a first semiconductor layer which comprises a first semiconductor material having a first bandgap; a second semiconductor layer which comprises a second semiconductor material having a second bandgap and a first conductivity type, and said second bandgap being greater than said first bandgap, whereby a two-dimensional electron gas is formed in said first layer; said device comprising source, gate, and drain electrodes on said second semiconductor layer; and the spacing between said gate and drain electrodes being in the range from 8 μm to 100 μm.
Claim 3
Dependent Claim
22 words
The device of claim 1 in which said gate electrode has a length in the range from 0.5 μm to 20 μm.
Claim 4
Dependent Claim
18 words
The device of claim 1, further comprising a semiconductor buffer layer between said first and second semiconductor layers.
Claim 5
Dependent Claim
25 words
The device of claim 1 in which said first and second semiconductor materials are selected from the group consisting of Group III-V compound semiconductor materials.
Claim 6
Dependent Claim
19 words
The device of claim 4 in which said Group III-V compound semiconductor materials comprise Al x Ga 1-x As.
Claim 7
Dependent Claim
23 words
The device of claim 4 in which said Group III-V compound semiconductor materials comprise In x Ga 1-x As y P 1-y .
Claim 8
Dependent Claim
8 words
The device of claim 6 in which y=1.
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) | 1991-04-19 | 1991-10-19 | 1992-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-19 | 1995-10-19 | 1996-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-19 | 1999-10-19 | 2000-04-19 | $7700.00 | Window Closed / Lapsed |