Evidence for Critical-Field Switching in Amorphous Semiconductor Materials

We have investigated the role of thermal and electronic effects in threshold switching in an amorphous semiconductor of memory composition. Evidence is presented to show that switching is a bulk field effect, and that, if thermal effects are discounted or eliminated, the switching field is independent of pulse width for pulses longer than 1 nsec. This was the shortest pulse width measured. Short-pulse (1.5 nsec) measurements indicate that a previously unreported conduction region is established at the critical switching field.