Analysis of the lateral insulated gate transistor

On-state characteristics of the Lateral Insulated Gate Transistor (LIGT) have been investigated and modeled with the aid of two-dimensional simulations. It is shown that the LIGT is characterized by several distinct on-state regimes: DMOS, bipolar, and thyristor-latchup; which are identified by the respective conduction mechanisms for each mode. Furthermore, the geometry of the shorted anode determines the transition from the DMOS regime to the bipolar regime, whereas the geometry of the p-well determines the transition to thyristor behavior. Devices have been fabricated with latchup currents greater than 2 A/cm.