The "Thyristor"—A new high-speed switching transistor

A description is given of the construction and characteristics of a versatile and novel semiconductor device, called a "Thyristor," that may be operated as a bistable element switching to a high conductivity mode or as a more conventional high-frequency transistor, either in switching or amplifying circuitry. The Thyristor has thyratron-like characteristics that closely approach those of an ideal switch. However, the Thyristor, unlike the thyratron, can be turned off readily by the control element. The open-state current is about 2 microamperes and the closed-state voltage drop is 0.3 to 0.5 volt. The unit can be switched into the high conductance mode in less than 0.1 microsecond with a pulse energy of 10^-4ergs. It can be turned off with a pulse energy of about 10^-1ergs in times of the order of 0.1 microsecond. The bistable operation depends upon a new type of semiconductor contact that collects holes at low current densities and injects electrons at high current densities. The electron alpha of the injector increases as a power law function of current and greatly aids in obtaining device reproducibility. These injector properties can be described in terms of a tunneling mechanism.