A NEW DELTA-DOPED INGAAS/GAAS PSEUDOMORPHIC HIGH-ELECTRON-MOBILITY TRANSISTOR UTILIZING A STRAINED SUPERLATTICE SPACER

A new delta-doped In0.18Ga0.82As/GaAs pseudomorphic high electron mobility transistor (HEMT) utilizing an In0.18Ga0.82As/GaAs strained superlattice spacer grown by low-pressure metal organic chemical vapor deposition (LP-MOCVD) has been prepared. For a gate length of 5 mum, the present structure reveals superior saturation current density (180 mA/mm at 300 K and 230 mA/mm at 77 K) and extrinsic transconductance (103 mS/mm at 300 K and 142 mS/mm at 77 K). The current-voltage characteristics are superior to those of reported similar InGaAs/GaAs structure with gate length of 2 mum grown by molecular beam epitaxy (MBE). Also, because of the undoped cap layer grown on the top of the delta-doped GaAs, a breakdown voltage of 10 V has been achieved.