Study of subthreshold electron mobility behavior in SOI-MESFETs

Micropower circuits based on sub-threshold MOSFETs are used in a variety of applications ranging from digital watches to medical implants. Alternate device structures are needed that will satisfy both the low-power and RF requirements and will allow much better operation of, for example, pacemakers. A candidate structure is the SOI-MESFET that is currently being fabricated and theoretically characterized within our Nanostructures Research Group at Arizona State University. Since the mobility is the key factor in determining the device cut-off frequency, it is the purpose of this study to investigate the electron mobility improvement of SOI MESFET when compared to SOI and conventional MOSFET devices. To accomplish this goal, we have utilized our in-house Ensemble Monte Carlo device simulator and performed extensive simulations of similar geometry SOI MOSFETs and Si MESFET channels.