E-beam-evaporated Al_2O_3 for InAs/AlSb metal-oxide-semiconductor HEMT development

摘要

Considerable on-state impact ionization and off-state tunneling leakages are the two principal drawbacks of InAs/AlSb HEMTs, which have a small bandgap and type-II band lineup. This work introduced a wide-bandgap high-k Al_2O_3 between the gate metal and semiconductor surface and successfully demonstrated DC and RF performance of the InAs/AlSb metal-oxide-semiconductor HEMTs (MOS-HEMTs). An MOS-HEMT device with a 2.0 μm gate length yields DC performance of I_(DSS)= 286 mA/mm and G_m = 495 mS/ mm and RF performance of f_T=10.1 GHz and f_(MAX)=19.9 GHz. Compared with a conventional HEMT, gate leakage is reduced by one order and the marked dependence of drain current on gate bias in the deep subthreshold region is largely alleviated.