USH111H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gallium arsenide material and process evaluation by means of pulsed photoconductance in test devices
Assignee: United States Department of the Navy
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Filing: 1985-11-21
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Granted: 1986-08-05
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Expires: 2005-11-21
Abstract
Abstract A method is disclosed for determining characteristics of semi-insulating lium arsenide that can be used to evaluate the suitability of the material for semiconductor processing. An n-channel test device formed on a substrate of semi-insulating gallium arsenide is illuminated with pulses of light. The decay in the photoconductance that occurs due to the illumination is measured in order to enable characterization of the shallow acceptor impurities which compensate the deep donors in the semi-insulating gallium arsenide.
Inventors
- 👤 Larry D. Flesner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:41
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/302; G01R31/308; H; H10; H10F; H10F30/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
70 words
A method for determining characteristics of a substrate of semi-insulating gallium arsenide comprising the steps of: forming an n-channel on said surface of said gallium arsenide substrate; forming first and second contacts to said n-channel on said gallium arsenide substrate; applying a voltage to said first and second contacts; illuminating said n-channel with a set of light pulses from a light source; measuring the time dependent conductance of said n-channel.
Claim 2
Independent Claim
70 words
A method for determining characteristics of a substrate of semi-insulating gallium arsenide comprising the steps of: forming an n-channel on said surface of said gallium arsenide substrate; forming first and second contacts to said n-channel on said gallium arsenide substrate; applying a voltage to said first and second contacts; illuminating said n-channel with a set of light pulses from a light source; measuring the time dependent conductance of said n-channel.
Claim 3
Dependent Claim
29 words
The method of claim 1 further comprising the step of: measuring the contribution of said time dependent photoconductance that is attributable to the photovoltaice effect within said n-channel device.
Claim 4
Dependent Claim
67 words
The method of claim 1 wherein said step of applying a voltage to said first and second contacts comprises the step of: connecting an oscilloscope in parallel with a load resistor; connecting a voltage source in series with said parallel connected oscilloscope and load resistor; connecting said series connection of said voltage source and said parallel connected oscilloscope and load resistor, across said first and second contacts.
Claim 5
Dependent Claim
19 words
The method of claim 3 further comprising the step of connecting a computer to the output of said oscilloscope.
References Cited (Backward Citations)
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-04 | 1990-02-03 | 1990-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-04 | 1994-02-03 | 1994-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-04 | 1998-02-03 | 1998-08-05 | $7700.00 | Window Closed / Lapsed |