Low-voltage, high-speed AlSb-InAsSb HEMTs

We report on the fabrication and characteristics of antimonide-based HEMTs with an InAsSb channel. Infrared photoluminescence measurements at 5 K confirm that the addition of Sb changes the band structure from a staggered type-II heterojunction lineup to a type-I. These HEMTs with a 0.1 μm gate length exhibit decreased output conductance and improved voltage gain compared to previous AlSb/InAs HEMTs with similar gate length. At V_DS=0.6 V, a microwave transconductance of 700 mS/mm and an output conductance of 110 mS/mm were obtained corresponding to a voltage gain of 6. AlSb/InAs HEMTs have also been fabricated with a 60 nm gate length. These HEMTs exhibit-a low-field source-drain resistance of 0.35 Ω-mm and a measured f_T of 90 GHz at a drain voltage of only 100 mV. This f_T value is the highest reported for any FET at this drain voltage