120-nm gate-length In0.7Ga0.3As/In0.52Al0.48As InP-based HEMT

120 nm gate-length In 0.7 Ga 0.3 As/In 0.52 Al 0.48 As InP-based high electron mobility transitions (HEMTs) are fabricated by a new T-shaped gate electron beam lithograph (EBL) technology, which is achieved by the use of a PMMA/PMGI/ZEP520/PMGI four-layer photoresistor stack. These devices also demonstrate excellent DC and RF characteristics: the transconductance, maximum saturation drain-to-source current, threshold voltage, maximum current gain frequency, and maximum power-gain cutoff frequency of InGaAs/InAlAs HEMTs is 520 mS/mm, 446 mA/mm, −1.0 V, 141 GHz and 120 GHz, respectively. The material structure and all the device fabrication technology in this work were developed by our group.