Claims
- 1. 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.degree. C. to about 900.degree. C. and depositing an N-type layer of about 10 to 15 microns of SnO.sub.2 onto the top surface of said substrate,
- (c) depositing a P-type layer of about 10 microns of SnO.sub.2 on said N-type layer,
- (d) cooling the furnace at a rate of about 10.degree. C. per minute to about 600.degree. 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.
- 2. Method according to claim 1 wherein said N-type layer of SnO.sub.2 is obtained by doping with a member of the group consisting of antimony, arsenic, and phosphorus.
- 3. Method according to claim 2 wherein said N-type layer of SnO.sub.2 is obtained by doping with antimony.
- 4. Method according to claim 2 wherein said N-type layer of SnO.sub.2 is obtained by doping with arsenic.
- 5. Method according to claim 2 wherein said N-type layer of SnO.sub.2 is obtained by doping with phosphorus.
- 6. Method according to claim 1 wherein said P-type layer of SnO.sub.2 is obtained by doping with a member of the group consisting of indium, boron, aluminum, and gallium.
- 7. Method according to claim 6 wherein said P-type layer of SnO.sub.2 is obtained by doping with indium.
- 8. Method according to claim 6 wherein said P-type layer of SnO.sub.2 is obtained by doping with boron.
- 9. Method according to claim 6 wherein said P-type layer of SnO.sub.2 is obtained by doping with aluminum.
- 10. Method according to claim 6 wherein said P-type layer of SnO.sub.2 is obtained by doping with gallium.
- 11. Method according to claim 1 wherein said N-type layer of SnO.sub.2 is obtained by doping with antimony and wherein said P-type layer of SnO.sub.2 is obtained by doping with indium.
- 12. Method according to claim 1 wherein said N and P type layers are deposited by chemical vapor deposition.
- 13. Method according to claim 1 wherein said N and P type layers are deposited by vapor phase epitaxy.
- 14. Method according to claim 1 wherein said N and P type layers are deposited by sputtering.
- 15. Method according to claim 1 wherein said substrate is monocrystalline.
- 16. Method according to claim 15 wherein said monocrystalline substrate is selected from the group consisting of SnO.sub.2 and sapphire.
- 17. Method according to claim 16 wherein said monocrystalline substrate is SnO.sub.2.
- 18. Method according to claim 16 wherein said monocrystalline substrate is sapphire.
- 19. Method according to claim 1 wherein said substrate is polycrystalline.
- 20. Method according to claim 19 wherein said polycrystalline substrate is selected from the group consisting of polycrystalline quartz, polycrystalline SnO.sub.2, and polycrystalline sapphire.
- 21. Method according to claim 20 wherein said polycrystalline substrate is polycrystalline quartz.
- 22. Method according to claim 20 wherein said polycrystalline substrate is polycrystalline SnO.sub.2.
- 23. Method according to claim 20 wherein said polycrystalline substrate is polycrystalline sapphire.
- 24. Method according to claim 1 wherein the metal contact is selected from the group consisting of gold, molybdenum, moly-manganese silver, and nickel.
- 25. Method according to claim 24 wherein the metal contact is gold.
- 26. Method according to claim 24 wherein the metal contact is molybdenum.
- 27. Method according to claim 24 wherein the metal contact is moly-manganese silver.
- 28. Method according to claim 24 wherein the metal contact is nickel.
- 29. Method of forming an efficient electron emitter cold cathode, said method including the steps of:
- (a) placing an N-type wafer of SnO.sub.2 of about 500 microns in thickness in a furnace,
- (b) heating the furnace to about 900.degree. 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.sub.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.sub.2 of about 10 microns in thickness,
- (d) cooling the furnace at a rate of about 10.degree. C. per minute to about 600.degree. 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.sub.2 wafer.
Government Interests
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.
US Referenced Citations (3)