DEPLETION-MIS-LIKE INGAAS GAAS DELTA-DOPED STRUCTURES WITH HIGH BREAKDOWN VOLTAGE AND LARGE GATE VOLTAGE SWING/

Depletion-MIS-like GaAs/In0.25Ga0.75As/GaAs delta-doped heterostructur e field effect transistors (HFETs) have been successfully grown by low -pressure metalorganic chemical vapor deposition (LP-MOCVD). Hall mobi lities as high as 5600 (22000) and 3920 (18400) cm(2)/V.s with sheet c arrier densities of 2 (1.8) and 4.3 (2.5) x 10(12) cm(-2) for single a nd double delta-doped structures at 300 (77) K, respectively are achie ved. Breakdown voltages as high as 26 V for single and 16 V for double delta-doped structures are obtained. Meanwhile, the structures in thi s work reveal improved gate voltage swings. By virtue of the photolumi nescence (PL) spectra, most of the carriers transferring from the delt a-doped layer to the InGaAs channel at zero gate bias are found. Negat ive differential resistance (NDR) phenomena under illumination which d egrades the transconductances are also observed and discussed.