Enhancement mode metamorphic Al/sub 0.67/In/sub 0.33/As/Ga/sub 0.66/In/sub 0.34/As HEMT on GaAs substrate with high breakdown voltage

This paper presents original and experimental results provided by E-mode Al/sub 0.67/In/sub 0.33/As/Ga/sub 0.66/In/sub 0.34/As metamorphic HEMT. The devices exhibit good dc and rf performances. The 0.4 μm gate length devices have saturation current density of 355 mA/mm at +0.6 V gate-to-source voltage. The Schottky characteristic is a typical reverse gate-to-drain breakdown voltage of -16 V. It is the first time, to our knowledge, that gate current issued from impact ionization have been observed in these devices versus gate to drain extension. These results are the first reported for E-mode Al/sub 0.67/In/sub 0.33/As/Ga/sub 0.66/In/sub 0.34/As MM-HEMTs on GaAs substrate.