A HOT CARRIER PN-DIODE

• US 3,668,481 A
• Filed: 08/10/1970
• Issued: 06/06/1972
• Est. Priority Date: 12/26/1968
• Status: Expired due to Term

• Current Assignee: Jack L. Saltich, James L. Rutledge
• Original Assignee: Jack L. Saltich, James L. Rutledge
• Inventors: Rutledge, James L., Saltich, Jack L.
• Primary Examiner(s): Kallam, James D.
• Application Number:
  US05/062,665
• Time in Patent Office: 666 Days
• Field of Search: 317/234,235
• US Class Current: 257/481
• CPC Class Codes: H01L 21/00 Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
• CPC Class Codes: H01L 21/24 Alloying of impurity materials, e.g. doping materials, electrode materials, with a semiconductor body H01L21/182 takes precedence
• CPC Class Codes: H01L 29/00 Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor H01L31/00 - H01L33/00, H10K10/00, H10N take precedence; details other than of semiconductor bodies or of electrodes thereof H01L23/00; devices consisting of a plurality of solid state components formed in or on a common substrate H01L27/00
• CPC Class Codes: H01L 29/06 characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
• CPC Class Codes: H01L 29/47 Schottky barrier electrodes H01L29/435 takes precedence
• CPC Class Codes: H01L 29/86 controllable only by variation of the electric current supplied, or only the electric potential applied, to one or more of the electrodes carrying the current to be rectified, amplified, oscillated or switched
• CPC Class Codes: Y10S 148/051 Etching

Abstract

Disclosed is a Schottky barrier or hot carrier diode and process for making same wherein a diffused PN junction and a Schottky barrier junction are both formed in a body of semiconductor material. The diffused PN junction is formed by first diffusing an impurity through an opening in a diffusion mask and into one surface of the semiconductor body to form PN junction. Next, a large central portion of the region formed by the above diffusion is removed by etching or cutting, leaving unaffected by the etchant only that portion of the diffused region underlying and adjacent to the diffusion mask on the surface of the semiconductor body. The latter portion of the diffused region forms a relatively small area diffused PN junction. Finally, a Schottky barrier junction is formed in the etched out area of the semiconductor body, and the diode including the diffused and Schottky barrier junctions has a near-ideal current-voltage characteristic and still maintains its fast recovery time.

Claims

1. A hot carrier Schottky barrier diode comprising:

a semiconductor body of one type conductivity and having an upper surface;

a passivating layer adherent to said upper surface and having an aperture formed therein;

a cavity in said body being exposed by said aperture;

an annular shaped region of opposite conductivity type formed in said body and encircling said cavity;

said region forming a PN junction with said body and having a first edge terminating at said upper surface and under said layer, and having a second edge terminating at the wall of said cavity;

a first contact member positioned in said cavity and extending up the walls of the cavity and overlying a portion of said passivating layer, said contact member forming a rectifying contact with said body for forming a Schottky barrier junction therewith and an ohmic contact with said region.

2. The diode defined in claim 1 wherein said first contact member being formed by material selected from the group consisting of aluminum, gold, silver and platinum silicide for providing a relatively high Schottky barrier height and a relatively low leakage current through said Schottky barrier junction.

3. The diode defined in claim 1 wherein said first contact member being formed by material selected from the group consisting of titanium, molybdenum, chromium and nickel for providing a relatively low Schottky barrier height and relatively high reverse leakage and high forward currents.

4. The diode defined in claim 2 which further includes a second contact member adherent to said first contact member for providing good bonding contact to said diode, said second contact member being formed by material selected from the group consisting of gold, aluminum, platinum and copper alloys.

5. The diode defined in claim 3 which further includes a second contact member adherent to said first contact member for providing good bonding contact for said diode, said second contact member being formed by material selected from the group consisting of gold, aluminum, platinum and copper alloys.