US 5,317,171 AGranted

MOS gated thyristor with remote turn-off electrode

AssigneeNorth Carolina State University

InventorsMallikarjunaswamy S. Shekar, Bantval J. Baliga

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Abstract

An emitter-switched thyristor structure includes a remote turn-off electrode for reducing turn-off time and increasing maximum controllable operating current. The switched thyristor structure further includes anode and cathode electrodes, with the remote electrode being connected to the cathode electrode. A multi-layer body of semiconductor material has a first surface, as well as regenerative and non-regenerative portions each operatively coupled between the anode and cathode electrodes. The regenerative portion includes adjacent first, second, third and fourth regions of alternating conductivity type arranged respectively in series. Electrical contacts exist between the remote electrode and the second region, as well as between the anode electrode and the fourth region. The thyristor is turned on by applying an enabling voltage to an insulated gate electrode disposed adjacent the first surface such that a conductive channel is created in the regenerative portion via modulation of the conductivity therein. Similarly, the termination of regenerative operation is initiated by applying a non-enabling voltage to the gate electrode. The remote electrode collects any charges remaining in the second region of the regenerative portion subsequent to application of the non-enabling voltage and thereby expedites turn off of the emitter-switched thyristor.

Claims9

Dependent claims

A semiconductor thyristor device comprising:

a substrate forming a drift region, a floating emitter region, a base region interposed between said drift region and said floating emitter region, and an anode region adjacent a portion of said drift region distal said base region, said base region being doped with P-type dopants to a first level of dopant concentration;
a cathode region comprising a P-well adjacent said drift region and an N-region in said P-well, said P-well being doped with P-type dopants to a second level of concentration;
wherein said second level of concentration exceeds said first level of concentration;
a cathode electrode coupled to said cathode region;
an anode electrode coupled to said anode region;
a first insulated gate forming a first MOS transistor connecting said cathode electrode to said drift region when said first MOS transistor is enabled;
a second insulated gate forming a second MOS transistor coupling said floating emitter region to said drift region when said second MOS transistor is enabled;
and
remote electrode means, coupled to said cathode electrode and to said base region and separated from said floating emitter region by said base region, for collecting charge carriers from said base region;
wherein a current path from said anode to said cathode is formed by said first and second MOS transistors when an enabling voltage is applied to said first and second insulated gates, and wherein, when a non-enabling gate voltage is applied to said first and second MOS transistors said current path is shut off and any charges remaining in said base region are collected by said remote electrode.

7 more elements

Dependencies are inferred from the claim text.