Abstract

This paper presents original results provided by combination of Enhancement-Mode (E-mode) with metamorphic growth of Al0.67In0.33As/Ga0.66In0.34As HEMT structure on a GaAs substrate. The devices, which are the first reported for Enhancement-Mode Al0.67In0.33As/Ga0.66In0.34As MM-HEMT’s, exhibits good dc and rf performance. Good Schottky characteristics have been obtained (a forward turn-on voltage of 0.9V and a typical reverse gate to drain breakdown voltage of 16 V). The 0.4µm gate length devices have a saturation current of 455 mA/mm at +0.8V gate voltage. Gate current studies, versus gate-to-drain extension have been observed, in the first time, in such as devices, showing gate current issued from impact ionization.