Switching phenomena in metal-insulator-n/p+ structures: theory, experiment and applications

Switching phenomena occurring in simple metal-semi-insulator- n/p+ devices are presented. The I-V characteristics comprise a high-impedance or OFF state during the initial voltage stages, which is quite stable for voltages up to the switching voltage, Vs. When Vs is exceeded, the device switches rapidly to a low-voltage, low-impedance or ON state, in which the current increases with almost no change in the voltage across the device. The two regions are separated by a negative-resistance region. Two modes of switching are identified, which are due to either to punch-through or avalanching occurring in the epitaxial n-layer. Each of these modes of operation are studied extensively, both experimentally and theoretically. The feature of these devices is that they are readily fabricated using standard i.e. fabrication techniques. Several applications of the devices are presented.