Method of manufacturing field-emitter

• US 5,358,909 A
• Filed: 02/26/1992
• Issued: 10/25/1994
• Est. Priority Date: 02/27/1991
• Status: Expired due to Fees

• Current Assignee: Nippon Steel Corporation
• Original Assignee: Nippon Steel Corporation
• Inventors: Kanazawa, Satoshi, Hashiguchi, Gen, Kawamura, Kazuhiko, Sakamoto, Hikaru
• Primary Examiner(s): Thomas, Tom
• Assistant Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US07/840,896
• Time in Patent Office: 972 Days
• Field of Search: 156/657, 156/647, 156/632, 156/641, 437/228, 303/309, 303/313, 303/336
• US Class Current: 438/20
• CPC Class Codes: H01J 9/025 of field emission cathodes

Abstract

A field-emitter having stable electrical properties, a long service life and a very small electron emission voltage is provided. The cathode of the element has a strongly sharpened projection at the tip end, and a smooth connection between the projection and the body portion. In the method of manufacturing the elements, cathodes are produced with a high reproducibility by using a mold produced by forming concave portions in the silicon and oxidizing the layer thereon, whereby the spacing between the cathode and the gate electrode is determined by the thickness of the silicon oxide layer, and the position of the cathode is determined by the silicon oxide layer embedded in the silicon substrate, by using an etching stop method based on an electrochemical etching process.

Claims

1. A method of manufacturing a vacuum microelectronic triode device, said method comprising the steps of:

(a) providing a substrate having a silicon layer at least adjacent to a top surface of the substrate, the silicon layer having a top surface;

(b) forming a recess in the silicon layer from the top surface thereof, said recess having a cross section, the sides of which intersect and form a sharp point at a bottom thereof, the silicon layer having a surface in the recess;

(c) oxidizing a portion of the silicon layer in the recess to form a first silicon oxide layer on the surface of the recess of the silicon layer;

(d) etching the silicon layer surrounding the first silicon oxide layer to a depth shallower than a depth of the bottom of the first silicon oxide layer, the etched silicon layer having a second top surface;

(e) oxidizing the second surface of the silicon layer to form a second silicon oxide layer;

(f) depositing a first electrically conductive layer on the first and second silicon oxide layers;

(g) depositing a third silicon oxide layer on the first electrically conductive layer;

(h) etching a portion of the third silicon oxide layer above said recess to form a first opening of the third silicon oxide layer on the first electrically conductive layer;

(i) depositing a second electrically conductive layer in the first opening and on the third silicon oxide layer;

(j) etching a portion of the second electrically conductive layer to form a second opening in the second electrically conductive layer on the third silicon oxide layer remote from the first opening;

(k) etching a portion of the third, first and second silicon oxide layers through the second opening to expose the first electrically conductive layer including the sharp point thereof in said recess; and

(l) closing the second opening with a protective layer under a vacuum.

2. A method of manufacturing a field emitter cathode having a sharp point at a tip thereof, said method comprising the steps of:

(a) providing a substrate;

(b) forming a stack of a first insulating layer, a first electrically conductive layer and a second insulating layer, in this order, on the substrate;

(c) forming an opening in said stack to expose the substrate;

(d) depositing a silicon layer in the opening and on the second insulating layer;

(e) oxidizing the silicon layer to form a silicon oxide layer having a recess, the sides of which recess 10 intersect and form a sharp point at the bottom thereof;

(f) depositing a second electrically conductive layer on the silicon oxide layer, the second electrically conductive layer having a sharp point in the recess of the silicon oxide layer; and

(g) removing at least a portion of the silicon oxide layer to expose the sharp point of the second electrically conductive layer.

3. A method of manufacturing a vacuum microelectronic triode device, said method comprising the steps of:

(a) providing a silicon substrate;

(b) forming a stack of a first insulating layer, a first electrically conductive layer and a second insulating layer, in this order, on the silicon substrate;

(c) forming a first opening in said stack to expose the substrate;

(d) depositing a silicon layer in the first opening and on the second insulating layer;

(e) oxidizing the silicon layer to form a silicon oxide layer having a recess, the sides of which recess intersect and form a sharp point at the bottom thereof;

(f) patterning the silicon oxide layer to leave a portion of the silicon oxide layer including an area on the first opening and to expose a portion of the second insulating layer;

(g) depositing a second electrically conductive layer on the patterned silicon oxide layer and the exposed second insulating layer, the second electrically conductive layer having a sharp point in the recess of the silicon oxide layer;

(h) forming a second opening in the second electrically conductive layer remote from the first opening;

(i) etching and removing the silicon oxide layer through the second opening to expose the sharp point of the second electrically conductive layer; and

(j) closing the second opening with a protective layer in a vacuum.