A transistor having an emitter and base with contact surfaces lying substantially in the same plane has an increased safe operating area, that is increased wattage rating without increasing the size of the transistor, achieved by providing an isolated base contact of an enhanced conductivity immediately adjacent the emitter, thereby providing a distributed resistance between the termination of the enhanced conductivity isolated base contact and the base ohmic contact of the transistor.
A power transistor design that eliminates thermally initiated secondary breakdown in fast, double-diffused transistors is described. The power dissipation capability is made independent of collector voltage, avoiding safe area restrictions below 0.9 BV.sub.CBO.
A high voltage transistor having successively an emitter zone, a highly doped base part, a low doped base part, a low doped collector part and a highly-doped collector part. At a distance from the highly doped base part, a groove is provided which extends down into the highly doped collector part and forms therebelow a channel stopper. The groove may be passivated with neutral, or, if desired, with positively charged glass or oxide while still maintaining a high collector-base breakdown voltage.
