The Impact of MOSFET channel width on its high power microwave damage effect

Two-dimensional simulation models were widely used in previous studies on high power microwave (HPM) effect on semiconductor device. The channel width, as the third dimension, has not yet been considered seriously. This article mainly focuses on the width effect on the electrical and thermal breakdown of MOSFET. Simulations of MOSFET with its drain injected by HPM are performed through the Sentaurus TCAD software. It shows that the “snapback” voltage decreases obviously with the increase of the channel width, thus the device with larger width will sustain the second breakdown for longer time in a condition of HPM injection. Besides, with the power injected from the drain, the smaller channel width of MOSFET is, the lower its peak temperature is. In addition, according to the principle of heat accumulation in the semiconductor device, a new kind of lightly doped drain (LDD) structure is proposed in this paper, which can improve the “snapback” voltage and the thermal diffusion along the width direction, resulting in enhancement of the device reliability.