Light activated thyristor with high di/dt capability

Claim 1

A light activated thyristor with high dI/dt capability comprising: A. first and second thyristors disposed in a semiconductor body having first and second major surfaces; each thyristor having four impurity regions extending through the body between the major surfaces; said impurity regions of alternate carrier-type disposed alternately with the PN junctions formed between adjacent regions; the two regions interior being cathode-base and anode-base regions, and the two regions adjoining the first and second major surfaces and adjoining the cathode-base and anode-base regions,respectively, being cathode-emitter and anode-emitter regions, respectively; B. the cathode-base, anode-base and anode-emitter regions of the first and second thyristors being common to both thyristors; C. said common cathode base region adjoining the first major surface intermittently of the cathode-emitter region of the first thyristor to form shunts, and between the cathode-emitter regions of the first and second thyristor such that the cathode-emitter regions are spaced apart; D. portions of the fiRst surface adjoining the cathode-emitter region of the second thyristor adapted for activation of the second thyristor therethrough by electromagnetic radiation of wavelengths corresponding substantially to the bandgap energy of the semiconductor material of the body; E. cathode and anode electrodes disposed on first and second major surfaces, respectively, of the semiconductor body and making ohmically contact with the cathode-emitter region of the first thyristor and the common anode-emitter region of both thyristors, respectively, said cathode electrode also making ohmic contact with the cathode-base region at the shunts through the cathode-emitter region of the first thyristor; and F. a floating contact positioned on the first major surface to make ohmic contact with the common cathode-base region between the thyristors and the cathode-emitter region of the second thyristor, while leaving exposed for light activation therethrough substantial portions of the first major surface adjoining the cathode-emitter region of the second thyristor.