Two-dimensional metal-semiconductor field effect transistor for ultra low power circuit applications

We describe a novel 2-dimensional metal-semiconductor field effect transistor (2-D MESFET) in which opposing Schottky side gates formed on the sidewall of a modulation-doped AlGaAs-InGaAs heterostructure modulate the channel width and the drain current. The drain current ranged from 0 to 210 /spl mu/A and the maximum measured transconductance was 212 /spl mu/S (212 mS/mm) at room temperature for a 1/spl times/1 micron channel. The threshold voltage was -0.45 V and the subthreshold ideality factor was 1.30. The estimated gate capacitance was 0.8 fF//spl mu/m, or about half the equivalent capacitance of conventional HFET's. The cutoff frequency f/sub T/ was estimated to be 21 GHz. The narrow channel effect, which limits the minimum power consumption in conventional FET's, is practically eliminated in this device.<<ETX>>