ZNSE FIELD-EFFECT TRANSISTORS

We report the first demonstration of ZnSe metal-semiconductor field-effect transistors. These new devices were fabricated from n-type Cl-doped epitaxial ZnSe layers grown by molecular beam epitaxy on (100) oriented semi-insulating Cr-doped GaAs substrates. Epitaxial layers with room-temperature carrier concentrations of 1.6×1017 cm-3 and electron mobilities ranging from 400 to 500 cm2/V s were used for device fabrication. Au was used as a Schottky gate contact. Either In or a multilevel metallization scheme using Cr and In was employed for the source and drain ohmic contacts. Depletion-mode transistor operation was observed for structures with 5 and 100 μm gate lengths and varying gate widths. The 5 μm gate length by 200 μm gate width device structures exhibited transconductances of 0.5 mS/mm.