SCHOTTKY-BARRIER-COLLECTOR TRANSISTOR

In saturated switching conventional n-p-n or p-n-p junction bipolar transistors the turn-off speed is limited by storage-time. The conventional way to reduce storage time is to control minority-lifetime by gold-doping. But gold-doping also decreases β, which is proportional to the minority lifetime, hence cannot eliminate the problem. The storage-time can be practically eliminated by replacing the conventional p-n collector junction by a Schottky-barrier, with the metallic side forming the collector region. This eliminates the injection of minority-carriers from the collector into the base region, as well as minority charge storage in the collector region. Theoretically the storage-time is thereby approximately β times less than that of the best possible gold-doped transistor with similar geometry and β. © 1968.