Pnpn semiconductor switching devices with stabilized firing characteristics

Claim 1

A SEMICONDUCTOR SWITCHING DEVICE INCLUDING IN COMBINATION, A. A BODY OF SEMICONDUCTOR MATERIAL HAVING A. FOUR REGIONS OF ONE AND THE OPPOSITE CONDUCTIVITY TYPE INTERLEAVED TO DEFINE THREE PN JUNCTIONS THEREBETWEEN, B. A PAIR OF MAIN CURRENT CARRYING ELECTRODES EACH IN LOW RESISTANCE OHMIC CONTACT WITH ONE OF THE EXTERNAL REGIONS OF SAID FOUR REGIONS WHEREBY A CURRENT PATH IS PROVIDED THROUGH SAID FOUR REGIONS BETWEEN SAID PAIR OF MAIN CURRENT CARRYING ELECTRODES, C. A GATE EMITTER REGION FORMED IN ONE OF SAID INTERNAL REGIONS OF SAID BODY OF SEMICONDUCTOR MATERIAL AND HAVING THE OPPOSITE TYPE CONDUCTIVITY FROM THAT ADJACENT INTERNAL REGION, D. A THIRD ELECTRODE IN LOW RESISTANCE OHMIC CONTACT WITH SAID GATE EMITTER REGION THEREBY TO PROVIDE A GATE ELECTRODE FOR SUPPLYING GATE FIRING CURRENT TO THE SEMICONDUCTOR SWITCHING DEVICE AND E. A HIGHLY DOPED REGION FORMED STRADDLING A PORTION OF THE JUNCTION BETWEEN SAID GATE EMITTER REGION AND SAID ADJACENT INTERNAL REGION THEREBY TO FORM A TUNNEL JUNCTION THEREBETWEEN AND REDUCE SENSITIVITY OF GATE FIRING CURRENT TO TEMPERATURE VARIATIONS.