Micro vacuum device

• US 5,463,277 A
• Filed: 12/06/1993
• Issued: 10/31/1995
• Est. Priority Date: 12/07/1992
• Status: Expired due to Term

• Current Assignee: Mitsuteru Kimura
• Original Assignee: Ricoh Company Limited
• Inventors: Honma, Masato, Kimura, Mitsuteru
• Primary Examiner(s): Pascal, Robert J.
• Assistant Examiner(s): GAMBINO, DARUIS
• Application Number:
  US08/161,609
• Time in Patent Office: 694 Days
• Field of Search: 313/306, 313/309, 313/310, 313/336, 315/169.1
• US Class Current: 315/169.1
• CPC Class Codes: H01J 1/20 Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment
• CPC Class Codes: H01J 21/105 with microengineered cathode and control electrodes, e.g. Spindt-type

Abstract

In the micro vacuum device according to the present invention, an electron emitter is formed into a thin film form on a thin film heater rising in midair by means of air bridge, or a thin film heater is formed as an electron emitter, and the electron emitter is provided adjacent to a gate with a space therebetween so that field emission of electrons is easily effected, or the electron emitter is heated so that thermoelectrons are easily emitted.

Claims

1. A micro vacuum device having an electron emitter, a gate, and a collector each provided in a vacuum, wherein said electron emitter is formed into a thin film form on a thin film heater rising in midair and said electron emitter is a provided over a portion of said gate with a space therebetween so that said electron emitter causes field emission of electrons.

2. A micro vacuum device according to claim 1, wherein said thin film heater is formed as said electron emitter.

3. A micro vacuum device according to claim 1, wherein an electric current flowing between said electron emitter and said collector is changed by changing a voltage loaded to said gate.

4. A micro vacuum device according to claim 1, wherein a tip section of said electron emitter provided adjacent to said gate is sharpened.

5. A micro vacuum device according to claim 1, wherein said electron emitter provided adjacent to said gate has a plurality of tip sections each facing the same thin film heater.

6. A micro vacuum device according to claim 1, wherein a slit is provided on said electron emitter.

7. A micro vacuum device according to claim 1, wherein a plurality of said collectors are provided adjacent to each other, and a strength as well as a direction of an external magnetic field is detected from a strength of an electric current flowing in said plurality of collectors.

8. A micro vacuum device according to claim 7, wherein said collector is formed into a thin film form.

9. A micro vacuum device according to claim 8, wherein said collector comprises a plurality of layers with an insulating thin film sandwiched therebetween.

10. A micro vacuum device according to claim 1, wherein a convex section is provided on a surface of said electron emitter.

11. A micro vacuum device according to claim 1, wherein, using a silicon single crystal chip with a concave section formed on the surface, a region including said concave section is sealed in a vacuum to form a micro vacuum region and electrodes of said electron emitter, gate and collector are extended via an insulating thin film to outside of said vacuum region.

12. A micro vacuum device having an electron emitter, a gate and a collector each provided in a vacuum, wherein said collector is formed from a conductive substrate, a gate electrode is provided via an insulating thin film on said collector, a hole is formed in said insulating thin film so that said collector is exposed to inside of said gate electrode, an electron emitter formed into a thin film form on a thin film heater is provided near a center of said hole, and said electron emitter is provided over a portion of said gate so that said electron emitter causes field emission of electrons.

13. A micro vacuum device according to claim 12, wherein said thin film heater is formed as said electron emitter.

14. A micro vacuum device according to claim 12, wherein an electric current flowing between said electron emitter and said collector is changed by changing a voltage loaded to said gate.

15. A micro vacuum device according to claim 12, wherein a tip section of said electron emitter provided adjacent to a center of said hole is sharpened.

16. A micro vacuum device according to claim 12, wherein the electron emitter provided adjacent to a center of said hole has a plurality of thin film heaters.

17. A micro vacuum device according to claim 12, wherein a slit is provided on said electron emitter.

18. A micro vacuum device according to claim 12, wherein a convex section is provided on a surface of said electron emitter.

19. A micro vacuum device according to claim 12, wherein, using a silicon single crystal chip with a concave section formed on the surface, a region including said concave section is sealed in a vacuum to form a micro vacuum, region, and electrodes of said electron emitter, gate and collector are extended via an insulating thin film to outside of said micro vacuum region.

20. A micro vacuum device formed on a silicon substrate having a main surface, comprising:

an insulating film formed on said main surface of said silicon substrate;

a gate formed on said insulating film;

a collector formed on said insulating film spaced apart from said gate; and

an electron emitter mounted on a thin film heater formed over and spaced apart from a portion of said gate.

21. The micro vacuum device according to claim 20, wherein the thin film heater and electron emitter are monolithically integrated.

22. The micro vacuum device according to claim 20, wherein an electric current flowing between said electron emitter mounted on a thin film heater and said collector is changed by changing a voltage loaded to said gate.

23. The micro vacuum device according to claim 20, wherein said electron emitter mounted on a thin film heater includes a sharpened tip section facing said collector.

24. The micro vacuum device according to claim 20, wherein said electron emitter mounted on a thin film heater includes a plurality of tip section facing the collector.

25. The micro vacuum device according to claim 20, wherein an upper surface of said electron emitter mounted on a thin film heater includes a slit.

26. The micro vacuum device according to claim 20, wherein said collector includes at least a first collector over a second collector with an insulating film therebetween, and a strength and direction of an external magnetic field is detected from a strength of an electric current flowing in said first and second collectors.

27. The micro vacuum device according to claim 26, wherein said collector is a thin film collector.

28. The micro vacuum device according to claim 27, wherein said collector consists of a first collector over a second collector with an insulting thin film therebetween.

29. The micro vacuum device according to claim 20, wherein an upper surface of said electron emitter mounted on a thin film heater has a convex section.

30. The micro vacuum device according to claim 20, further comprising a silicon single crystal chip having a concave area formed on a surface thereof, said silicon single crystal chip positioned on the micro vacuum device, sealing said gate, collector and electron emitter mounted on a thin film heater in a vacuum formed in said concave area, wherein

said electron emitter mounted on a thin film heater, gate and collector each have a electrode, and

the electrodes extend outside of said vacuum formed in said concave area via an insulating thin film.

31. A micro vacuum device formed on a silicon substrate having a main surface with a recess therein, comprising:

an insulating film formed on said main surface of said silicon substrate with an opening exposing at least a portion of said recess;

a ring-shaped gate and gate electrode formed on said insulating film with said ring-shaped gate having a circular opening over said recess;

a collector formed in the recess in said substrate proximate the center of said circular opening and exposed therethrough; and

a electron emitter mounted on a thin film heater positioned over said ring-shaped gate and having a sharpened tip positioned proximate the center of said circular opening facing said collector so as to cause field emission of electrons upon application of a voltage.

32. The micro vacuum device according to claim 31, wherein the thin film heater and electron emitter are monolithically integrated.

33. The micro vacuum device according to claim 31, wherein an electric current flowing between said electron emitter mounted on a thin film heater and said collector is changed by changing a voltage loaded to said gate.

34. The micro vacuum device according to claim 31, wherein said electron emitter mounted on a thin film heater includes at least two stacked conductive layers.

35. The micro vacuum device according to claim 32, wherein an upper surface of said electron emitter mounted on a thin film heater includes a slit.

36. The micro vacuum device according to claim 31, wherein an upper surface of said electron emitter mounted on a thin film heater has a convex section.

37. The micro vacuum device according to claim 31, further comprising a silicon single crystal chip having a concave area formed on a surface thereof, said silicon single crystal chip positioned on the micro vacuum device, sealing said gate, collector and electron emitter mounted on a thin film heater in a vacuum formed in said concave area, wherein

said electron emitter mounted on a thin film heater, gate and collector each have a electrode, and

the electrodes extend outside of said vacuum formed in said concave area via an insulating thin film.