US4149308A
Expired / Lapsed
US
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Method of forming an efficient electron emitter cold cathode
Assignee: United States Department of the Army
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Filing: 1977-12-16
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Granted: 1979-04-17
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Expires: 1997-12-16
Abstract
Abstract An efficient electron emitter cold cathode is formed by first placing an ype monocrystalline substrate of about 100 to about 500 microns in thickness in a furnace. The furnace is heated to about 850° C. to about 900° C. and an N-type layer of about 10 to 15 microns of SnO 2 is deposited onto the top surface of the substrate using a suitable carrier gas. Then, a P-type layer of about 10 microns of SnO 2 is deposited on the N-type layer. The furnace is then cooled at a rate of about 10° C. per minute to about 600° C. to form the emitter. The furnace is then cooled to room temperature and the emitter removed from the furnace. The emitter is subjected to etching and polishing to obtain a P-type layer of about 2 to 4 microns, and a nonreactive metal contact is then deposited on the P-type layer. The emitter is then completed by bonding a metal contact to the base of the N-type monocrystalline substrate.
Inventors
- 👤 Bernard Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:55
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/022
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
162 words
Method of forming an efficient electron emitter cold cathode, said method including the steps of: (a) placing an N-type substrate of about 100 to about 500 microns in thickness in a furnace, (b) heating the furnace to about 850° C. to about 900° C. and depositing an N-type layer of about 10 to 15 microns of SnO 2 onto the top surface of said substrate, (c) depositing a P-type layer of about 10 microns of SnO 2 on said N-type layer, (d) cooling the furnace at a rate of about 10° C. per minute to about 600° C. to form the emitter, (e) cooling the furnace to room temperature and removing the emitter from the furnace, (f) subjecting the P-type layer to etching and polishing to obtain a P-type layer thickness of about 2 to about 4 microns, (g) depositing a nonreactive metal contact on said P-type layer, and (h) bonding a metal contact to the base of the N-type monocrystalline substrate.
Claim 2
Dependent Claim
162 words
Method of forming an efficient electron emitter cold cathode, said method including the steps of: (a) placing an N-type substrate of about 100 to about 500 microns in thickness in a furnace, (b) heating the furnace to about 850° C. to about 900° C. and depositing an N-type layer of about 10 to 15 microns of SnO 2 onto the top surface of said substrate, (c) depositing a P-type layer of about 10 microns of SnO 2 on said N-type layer, (d) cooling the furnace at a rate of about 10° C. per minute to about 600° C. to form the emitter, (e) cooling the furnace to room temperature and removing the emitter from the furnace, (f) subjecting the P-type layer to etching and polishing to obtain a P-type layer thickness of about 2 to about 4 microns, (g) depositing a nonreactive metal contact on said P-type layer, and (h) bonding a metal contact to the base of the N-type monocrystalline substrate.
Claim 3
Dependent Claim
28 words
Method according to claim 1 wherein said N-type layer of SnO 2 is obtained by doping with a member of the group consisting of antimony, arsenic, and phosphorus.
Claim 4
Dependent Claim
18 words
Method according to claim 2 wherein said N-type layer of SnO 2 is obtained by doping with antimony.
Claim 5
Dependent Claim
18 words
Method according to claim 2 wherein said N-type layer of SnO 2 is obtained by doping with arsenic.
Claim 6
Dependent Claim
18 words
Method according to claim 2 wherein said N-type layer of SnO 2 is obtained by doping with phosphorus.
Claim 7
Dependent Claim
29 words
Method according to claim 1 wherein said P-type layer of SnO 2 is obtained by doping with a member of the group consisting of indium, boron, aluminum, and gallium.
Claim 8
Dependent Claim
18 words
Method according to claim 6 wherein said P-type layer of SnO 2 is obtained by doping with indium.
Claim 9
Dependent Claim
18 words
Method according to claim 6 wherein said P-type layer of SnO 2 is obtained by doping with boron.
Claim 10
Dependent Claim
18 words
Method according to claim 6 wherein said P-type layer of SnO 2 is obtained by doping with aluminum.
Claim 11
Dependent Claim
18 words
Method according to claim 6 wherein said P-type layer of SnO 2 is obtained by doping with gallium.
Claim 12
Dependent Claim
32 words
Method according to claim 1 wherein said N-type layer of SnO 2 is obtained by doping with antimony and wherein said P-type layer of SnO 2 is obtained by doping with indium.
Claim 13
Dependent Claim
18 words
Method according to claim 1 wherein said N and P type layers are deposited by chemical vapor deposition.
Claim 14
Dependent Claim
18 words
Method according to claim 1 wherein said N and P type layers are deposited by vapor phase epitaxy.
Claim 15
Dependent Claim
16 words
Method according to claim 1 wherein said N and P type layers are deposited by sputtering.
Claim 16
Dependent Claim
10 words
Method according to claim 1 wherein said substrate is monocrystalline.
Claim 17
Dependent Claim
20 words
Method according to claim 15 wherein said monocrystalline substrate is selected from the group consisting of SnO 2 and sapphire.
Claim 18
Dependent Claim
13 words
Method according to claim 16 wherein said monocrystalline substrate is SnO 2 .
Claim 19
Dependent Claim
11 words
Method according to claim 16 wherein said monocrystalline substrate is sapphire.
Claim 20
Dependent Claim
10 words
Method according to claim 1 wherein said substrate is polycrystalline.
Claim 21
Dependent Claim
25 words
Method according to claim 19 wherein said polycrystalline substrate is selected from the group consisting of polycrystalline quartz, polycrystalline SnO 2 , and polycrystalline sapphire.
Claim 22
Dependent Claim
12 words
Method according to claim 20 wherein said polycrystalline substrate is polycrystalline quartz.
Claim 23
Dependent Claim
14 words
Method according to claim 20 wherein said polycrystalline substrate is polycrystalline SnO 2 .
Claim 24
Dependent Claim
12 words
Method according to claim 20 wherein said polycrystalline substrate is polycrystalline sapphire.
Claim 25
Dependent Claim
22 words
Method according to claim 1 wherein the metal contact is selected from the group consisting of gold, molybdenum, moly-manganese silver, and nickel.
Claim 26
Dependent Claim
11 words
Method according to claim 24 wherein the metal contact is gold.
Claim 27
Dependent Claim
11 words
Method according to claim 24 wherein the metal contact is molybdenum.
Claim 28
Dependent Claim
12 words
Method according to claim 24 wherein the metal contact is moly-manganese silver.
Claim 29
Dependent Claim
11 words
Method according to claim 24 wherein the metal contact is nickel.
Claim 30
Dependent Claim
200 words
Method of forming an efficient electron emitter cold cathode, said method including the steps of: (a) placing an N-type wafer of SnO 2 of about 500 microns in thickness in a furnace, (b) heating the furnace to about 900° C. and depositing in vapor form on the top surface of the wafer a liquid suspension of tin chloride pentahydrate doped with antimony using nitrogen as a carrier gas to form an N-type layer of SnO 2 of about 15 microns in thickness, (c) depositing a liquid suspension of tin chloride pentahydrate doped with indium in vapor form on the N-type layer using nitrogen as a carrier gas to form a P-type layer of SnO 2 of about 10 microns in thickness, (d) cooling the furnace at a rate of about 10° C. per minute to about 600° C. to form the emitter, (e) cooling the furnace to room temperature and removing the emitter from the furnace, (f) subjecting the emitter to etching and polishing to obtain a P-type layer thickness of about 4 microns, (g) depositing a gold contact on the P-type layer, and (f) ultrasonically bonding a gold metal contact to the base of the N-type SnO 2 wafer.
Claim 31
Dependent Claim
200 words
Method of forming an efficient electron emitter cold cathode, said method including the steps of: (a) placing an N-type wafer of SnO 2 of about 500 microns in thickness in a furnace, (b) heating the furnace to about 900° C. and depositing in vapor form on the top surface of the wafer a liquid suspension of tin chloride pentahydrate doped with antimony using nitrogen as a carrier gas to form an N-type layer of SnO 2 of about 15 microns in thickness, (c) depositing a liquid suspension of tin chloride pentahydrate doped with indium in vapor form on the N-type layer using nitrogen as a carrier gas to form a P-type layer of SnO 2 of about 10 microns in thickness, (d) cooling the furnace at a rate of about 10° C. per minute to about 600° C. to form the emitter, (e) cooling the furnace to room temperature and removing the emitter from the furnace, (f) subjecting the emitter to etching and polishing to obtain a P-type layer thickness of about 4 microns, (g) depositing a gold contact on the P-type layer, and (f) ultrasonically bonding a gold metal contact to the base of the N-type SnO 2 wafer.
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) | 1982-04-16 | 1982-10-16 | 1983-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-16 | 1986-10-16 | 1987-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-16 | 1990-10-16 | 1991-04-17 | $7700.00 | Window Closed / Lapsed |