US4168212A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Determining semiconductor characteristic
Assignee: Post Office
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Filing: 1978-04-25
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Granted: 1979-09-18
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Expires: 1998-04-25
Abstract
Abstract The electrochemical measuring technique of the present invention employs, as the barrier material, a concentrated electrolyte, which also forms a medium for the controlled dissolution of a surface of the semiconductor so as to provide a continuous depth profile. The depth profile characteristic may be determined by capacitance-voltage measurements on n-type bulk GaAs, using KOH as the electrolyte.
Inventors
- 👤 Marc M. Faktor
- 👤 Thomas Ambridge
- 👤 Ean G. Bremner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:12
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/227; H; H10; H10P; H10P74/00; H10P74/20; H10P74/207
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
94 words
A method for determining carrier concentration as a function of depth in a semiconductor material comprising mounting the semiconductor material in an electrolytic cell so that electrolyte in the cell is in contact with the semiconductor material, applying a d.c. voltage to the material and electrolyte to simultaneously form a Schottky diode between the material and electrolyte and bring about anodic etching at the surface of the material with the aid of the electrolyte, applying an a.c. voltage to said Schottky diode, and measuring the capacitance of the depletion layer of the Schottky diode.
Claim 2
Independent Claim
94 words
A method for determining carrier concentration as a function of depth in a semiconductor material comprising mounting the semiconductor material in an electrolytic cell so that electrolyte in the cell is in contact with the semiconductor material, applying a d.c. voltage to the material and electrolyte to simultaneously form a Schottky diode between the material and electrolyte and bring about anodic etching at the surface of the material with the aid of the electrolyte, applying an a.c. voltage to said Schottky diode, and measuring the capacitance of the depletion layer of the Schottky diode.
Claim 3
Dependent Claim
23 words
A method according to claim 1, including the step of modulating the a.c. voltage and measuring the differential capacitance of the depletion layer.
Claim 4
Dependent Claim
20 words
A method according to claim 1, including illuminating the surface of said material to provide minority carriers at the surface.
Claim 5
Dependent Claim
19 words
A method according to claim 3, wherein the surface is illuminated by light having a predetermined range of frequency.
Claim 6
Dependent Claim
38 words
A method according to claim 1, including the step of providing a continuous graphical plot of the relationship between carrier concentration at the surface of the Schottky diode and the thickness of the semiconductor etched from said area.
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) | 1982-09-17 | 1983-03-19 | 1983-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-17 | 1987-03-19 | 1987-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-17 | 1991-03-19 | 1991-09-18 | $7700.00 | Window Closed / Lapsed |