Patent US3545342A successfully refreshed from Google Patents.
US5374589A
Expired / Lapsed
US
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Process of making a bistable photoconductive component
Assignee: United States Department of the Navy
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Filing: 1994-04-05
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Granted: 1994-12-20
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Expires: 2014-04-05
Abstract
Abstract Semi-insulating gallium arsenide wafers manufactured with varying silicon nsity shallow donors are copper compensated by heating to temperature of at least 550° C. to thermally diffuse the copper into the wafers and thereby provide deep copper acceptors in the wafer. Higher annealing temperatures are employed for higher concentrations of silicon in the wafers and the thermal diffusion is accomplished in the presence of copper, and in some instances, in the presence of varying quantities of arsenic. The copper compensated, silicon doped, gallium arsenide wafers obtained have the electrical property characteristic capability of being used as photoconductive switching components. In one aspect of the invention the silicon doped gallium arsenide wafer is sealed in a quartz ampoule in the presence of solid copper and solid arsenic and heated to the annealing temperature. In another aspect of the invention, the copper and arsenic are flowed as vapors over the silicon doped gallium arsenide wafer disposed in a reaction tube within a diffusion furnace, while the wafer is heated to the annealing temperature.
Inventors
- 👤 Randy A. Roush
- 👤 Michael S. Mazzola
- 👤 David C. Stoudt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:25
CPC Classifications
H; H10; H10F; H10F77/00; H10F77/10; H10F77/12; H10F77/124; H10F77/1243; G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/134; G02B6/1342; H10F30/00; H10F71/00; H10F71/128; H10P; H10P32/00; H10P32/10; H10P32/17; H10P32/174; H10P32/18; H10P95/00; H10P95/40; H10P95/408; G02B2006/12166; G02B2006/12169; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/544; Y02P; Y02P70/00; Y02P70/50; Y10; Y10S; Y10S438/00; Y10S438/90; Y10S438/914; Y10S438/919
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
100 words
A method of making a copper compensated, silicon doped, gallium arsenide crystal for use as a photoconductive switching component, comprising: (a) providing a gallium arsenide wafer having a known quantity of a shallow silicon donor formed therein; (b) incrementally heating the silicon doped gallium arsenide wafer in the presence of copper over an extended period of time to an annealing temperature of at least 550° C.; and (c) cooling the heated silicon doped, gallium arsenide wafer to recover a copper compensated, silicon doped, gallium arsenide wafer having the electrical property characteristic capability of being used as a photoconductive switching component.
Claim 2
Independent Claim
100 words
A method of making a copper compensated, silicon doped, gallium arsenide crystal for use as a photoconductive switching component, comprising: (a) providing a gallium arsenide wafer having a known quantity of a shallow silicon donor formed therein; (b) incrementally heating the silicon doped gallium arsenide wafer in the presence of copper over an extended period of time to an annealing temperature of at least 550° C.; and (c) cooling the heated silicon doped, gallium arsenide wafer to recover a copper compensated, silicon doped, gallium arsenide wafer having the electrical property characteristic capability of being used as a photoconductive switching component.
Claim 3
Dependent Claim
84 words
The method of claim 1 wherein the step of incrementally heating the silicon doped gallium arsenide wafer in the presence of copper includes the steps of: positioning the silicon doped wafer in a quartz ampoule disposed in a three zone furnace oven; providing a quantity of copper in the quartz ampoule; evacuating the quartz ampoule to a low pressure of <5×10 -6 Torr; and, sealing the quartz ampoule prior to incrementally heating the oven furnace to the annealing temperature of at least 550° C.
Claim 4
Dependent Claim
24 words
The method of claim 2 including the step of adding a solid mass of arsenic within the ampoule prior to sealing and heating thereof.
Claim 5
Dependent Claim
26 words
The method of claim 3 wherein the quantity of copper is obtained by providing a coating of copper on the inside surface of the quartz ampoule.
Claim 6
Dependent Claim
29 words
The method of claim 3 wherein the quantity of copper is provided by positioning a quantity of copper foil on a surface of the silicon doped gallium arsenide wafer.
Claim 7
Dependent Claim
30 words
The method of claim 3 wherein the quantity of copper is provided by a vapor coating of copper being provided on the surface of the silicon doped gallium arsenide wafer.
Claim 8
Dependent Claim
27 words
The method of claim 3 wherein the solid mass of arsenic is selected from quantities of arsenic consisting of 2, 14 and 93 mg solid arsenic masses.
Claim 9
Dependent Claim
28 words
The method of claim 7 wherein the presence of copper during heating of the silicon doped gallium arsenide wafer consists of a mass of 3 mg of copper.
Claim 10
Dependent Claim
63 words
The method of claim 1 wherein the step of incrementally heating the silicon doped gallium arsenide wafer includes the steps of: positioning the silicon doped gallium arsenide wafer in a reaction tube loaded in a diffusion furnace; and, flowing copper vapor into the reaction tube while the diffusion furnace is incrementally heated to at least 550° C. to provide the presence of copper.
Claim 11
Dependent Claim
38 words
The method of claim 9 including the step of flowing arsenic vapor into the reaction tube while the diffusion furnace is incrementally heated to at least 550° C. to provide a presence of arsenic within the diffusion furnace.
Claim 12
Dependent Claim
69 words
The method of claim 1 wherein the silicon doped gallium arsenide wafer is provided with a silicon density selected from the group of silicon densities consisting of 1×10 16 cm -3 ; 2×10 16 cm -3 ; 6×10 16 cm -3 ; and 7×10 17 cm -3 , and the incremental heating step includes heating the furnace to a temperature in the range of 550° C. to 875° C.
Claim 13
Dependent Claim
106 words
A thermal diffusion method of copper compensating silicon doped gallium arsenide wafers to facilitate the use thereof as switching components in photoconductive switches, comprising the steps of: providing a silicon doped gallium arsenide wafer having a silicon density selected from the group of silicon densities consisting of 1×10 16 cm -3 ; 2×10 16 cm -3 ; 6×10 16 cm -3 ; and 7×10 17 cm -3 ; and, incrementally heating the silicon doped gallium arsenide wafer in the presence of copper over a six hour period and in the temperature range of 550° C. to 875° C. to thermally diffuse the copper into the wafer.
Claim 14
Dependent Claim
106 words
A thermal diffusion method of copper compensating silicon doped gallium arsenide wafers to facilitate the use thereof as switching components in photoconductive switches, comprising the steps of: providing a silicon doped gallium arsenide wafer having a silicon density selected from the group of silicon densities consisting of 1×10 16 cm -3 ; 2×10 16 cm -3 ; 6×10 16 cm -3 ; and 7×10 17 cm -3 ; and, incrementally heating the silicon doped gallium arsenide wafer in the presence of copper over a six hour period and in the temperature range of 550° C. to 875° C. to thermally diffuse the copper into the wafer.
Claim 15
Dependent Claim
32 words
The method of claim 12 wherein the step of incrementally heating the silicon doped gallium arsenide wafer in the presence of copper also includes the step of providing a presence of arsenic.
Claim 16
Dependent Claim
54 words
The method of claim 13 wherein the step of incrementally heating the silicon doped gallium arsenide wafer is employed after the wafer is positioned with in a quartz ampoule and wherein the presence of copper and the presence of arsenic is attained by providing separate masses of arsenic and copper within the quartz ampoule.
Claim 17
Dependent Claim
28 words
The method of claim 14 wherein the separate mass of arsenic is selected from solid arsenic mass quantities consisting of 2, 14 and 93 mg solid arsenic masses.
Claim 18
Dependent Claim
19 words
The method of claim 14 wherein the separate mass of copper consists of a 3 mg mass of copper.
Claim 19
Dependent Claim
47 words
The method of claim 12 wherein the gallium doped gallium arsenide wafer is placed in a quartz ampoule disposed within a furnace oven to perform the step of incrementally heating thereof and the presence of copper is attained by providing a copper lining within the quartz ampoule.
Claim 20
Dependent Claim
50 words
The method of claim 12 wherein the silicon doped gallium arsenide wafer is placed in a quartz ampoule disposed within a furnace oven to perform the step of incrementally heating thereof and the presence of copper is attained by providing a copper coating on the silicon doped gallium arsenide wafer.
Claim 21
Dependent Claim
43 words
The method of claim 12 wherein the silicon doped gallium arsenide wafer is placed in a reaction tube disposed in a diffusion furnace and the presence of copper is attained by flowing a copper vapor over the wafer during the incremental heating thereof.
Claim 22
Dependent Claim
25 words
The method of claim 19 including the step of also flowing arsenic vapor over the silicon doped gallium arsenide wafer during the incremental heating thereof.
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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) | 1997-12-19 | 1998-06-20 | 1998-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-19 | 2002-06-20 | 2002-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-19 | 2006-06-20 | 2006-12-20 | $7700.00 | Window Closed / Lapsed |