Controlled rectifier having high rate-of-rise-of-current capability and low firing gate current

Claim 1

A controllably conductive semiconductor device having a high rate-of-rise-of-current capability and which can be fired with a relatively low gate current, comprising: a wafer of monocrystalline semiconductor material having first and second parallel surfaces; first, second and third spaced P-N junctions sequentially disposed therein; at least a portion of said third P-N junction terminating along said first surface of said wafer and dividing said first surface into a first surface region extending atop said third P-N junction and into a second surface region; a first main electrode connected to said first surface region of said first surface; a second main electrode connected to said second surface of said wafer; a fourth P-N junction disposed beneath said second surface region of said first surface and above said second P-N junction and being laterally displaced from said third P-N junction solely at one side thereof; an auxiliary electrode connected to said second surface region atop said fourth junction; said auxiliary electrode having a surface area smaller than the surface area of said first main electrode; a main gate electrode connected to said second surface region adjacent said auxiliary electrode; and an auxiliary gate electrode connected to said auxiliary electrode and to said second surface region of said wafer and adjacent to said first main electrode; said auxiliary electrode and said auxiliary gate electrode comprising a common conductive electrode extending across said fourth P-N junction; said auxiliary electrode being disposed between said main gate electrode and said first main electrode; the confronting edges of said first main electrode and said common conductive electrode being substantially coextensive; said common conductive electrode and said first main electrode consisting of spaced segments of a common metallic disc.