Fabrication & characterization of Schottky junction transistors

Micropower devices based on weakly inverted CMOS are commonly used in biomedical applications including pacemakers, artificial cochleas and retinas as well as for covert sensing. These devices use very little power but operate at comparatively low frequencies. Recently, the Schottky junction transistor (SJT) has been proposed as an alternative micropower device capable of operating at GHz frequencies. The SJT resembles an enhancement mode SOI MESFET, which uses the gate current to control a larger drain current. The channel thickness and doping are chosen such that the gate and drain currents vary exponentially with the gate voltage while maintaining a current gain (/spl beta/=I/sub d//I/sub g/) greater than unity. We describe experimental measurements that confirm the operating principle of prototype SJT devices. We also perform numerical simulations of a device with L/sub g/=0.5/spl mu/m.