A new ’’surface-states’’ mode of switching in M-thin insulator-n-p+ devices

Abstract

The metal-insulator (tunnel) -n-p device (MISS) is known to display current-controlled negative resistance in its I-V characteristics. This negative resistance behavior originates from a positive feedback interaction between the p-n junction and the tunnel metal insulator semiconductor (MIS) parts of the device. The simple structure of the MISS and its amenability to integration has so far been masked by the incomplete understanding of the physics of operation of the device. In this paper, the effect of the surface states at the semiconductor-insulator interface on the MISS behavior is considered. It is shown that the bias dependence of the charge stored in the surface states reduces the switching voltage Vw below the punch-through or avalanche breakdown limits. A simplified model of the MISS is developed taking into account the different roles of the surface states as charge storage centers, recombination centers, and tunnel-current carrying sites. This model is believed to bridge the gap between the previous theoretical models and experimental works.