Threshold switching integrated circuit and method for forming the same

• US 3,943,554 A
• Filed: 02/10/1975
• Issued: 03/09/1976
• Est. Priority Date: 07/30/1973
• Status: Expired due to Term

• Current Assignee: Signetics Corporation
• Original Assignee: Signetics Corporation
• Inventors: Muller, Richard S., Dao, Tich T., Russell, Lewis K.
• Primary Examiner(s): Miller, Jr., Stanley D.
• Assistant Examiner(s): Clawson, Jr., Joseph E.
• Application Number:
  US05/548,825
• Time in Patent Office: 393 Days
• Field of Search: 357/12, 357/13, 357/15, 357/34, 357/65, 357/91, 357/40
• US Class Current: 257/105
• CPC Class Codes: H01L 27/0761 Vertical bipolar transistor in combination with diodes only
• CPC Class Codes: H01L 27/0766 with Schottky diodes only
• CPC Class Codes: H03K 17/04126 in bipolar transistor switches

Abstract

A high speed threshold switching integrated circuit including a transistor and an integrally formed tunnel diode connected in parallel between the base and emitter of the transistor. The heavy doping necessary for the tunnel diode is achieved through the use of ion implantation. A current pulse applied to the emitter-base contact of the integrated circuit causes no collector current to flow until the point at which the rising current pulse exceeds the peak current of the tunnel diode. As the tunnel diode goes into the negative resistance region the transistor is turned on and rapidly pushed into near saturation with a consequent rapidly rising collector current.

Claims

1. An integrated circuit comprising a silicon semiconductor body of first conductivity type and having a generally planar top surface, a base region of a second conductivity type formed in said semiconductor body and being defined by a first dishshaped PN junction extending to the surface, an emitter region of said first conductivity type formed in said base region and being defined by a second PN junction extending to the surface, a tunnel diode region of said second conductivity type formed in said base region extending to and terminating at said surface and extending laterally with respect to said surface to overlap a portion of said second PN junction, said tunnel diode region having a high doping concentration relative to said base region together with metallization carried by said surface forming solely in combination with said surface a combination metallization contact partially overlying and making contact at said surface to said collector, said base and said tunnel diode regions and an additional contact to said emitter region to form a Schottky-clamped threshold switched integrated circuit.