Breakdown behavior of low-power pseudomorphic AlGaAs/InGaAs 2-D MESFET's

We report the breakdown behavior of the two-dimensional (2-D) MESFET, which is a low-power heterodimensional transistor having dual side gates that contact the edge of the two-dimensional electron gas (2-DEG) channel in a double-side planar-doped pseudomorphic Al/sub 0.24/Ga/sub 0.76/As/In/sub 0.17/Ga/sub 0.83/As material structure. Low output conductance (less than 6 mS/mm for V/sub GS/=0 V) and low gate leakage current (less than 100 nA) are measured out to a drain-source bias of 20 V, indicating that the effects of impact ionization are reduced in the 2-D MESFET. Excellent off-state drain-source and drain-gate breakdown voltages are experimentally measured to be 20 and 21 V, respectively. We attribute these high breakdown values to the electric and geometric properties of the heterodimensional Schottky metal/2-DEG junction.