Germanium power switching devices

Two-terminal and three-terminal germanium power switching devices have been developed, utilizing a metal semiconductor contact as an electron injector in a multijunction device. The principles of operation, fabrication techniques, and electrical characteristics of this new device are discussed. Devices capable of switching up to 25 amperes and blocking up to 350 volts have been fabricated and applied to power control circuits. The low impedance voltage drop is of the order of 0.5 volt and the dynamic resistance is a few hundredths of an ohm. A switch-on time less than 0.1 microsecond has been measured with a switch-off time of the order of microseconds.