The effect of surface roughness on the performance of InP MOSFETs

Results of a Monte Carlo simulation of inversion layer transport in InP devices at both high and low fields are presented. They show that the low-field mobility and the peak electron velocity decrease with increasing surface roughness and interface charge. However, at high fields the average electron velocity for the different surfaces converge and become nearly independent of the surface condition. This suggests that as the MOSFET is scaled down, the device performance will become independent of interface quality. Velocity-field, transit-time-channel-length, and transit-time-surface-roughness curves for InP MIS structures are presented. From these, qualitative estimates of device performance are obtained in terms of the surface roughness.<>