Aluminum-free GaInP/GaInAs pHEMTs for low-noise applications with peak fT = 256 GHz and peak fMAX = 360 GHz

Al-free HEMTs show advantageous characteristics in terms of LF-noise, low-temperature performance, breakdown behavior, high-frequency power performance as well as reliability [1]. In the present work, we report the technology and performance of 100 nm gate length Al-free GaInP/GaInAs pseudomorphic HEMTs grown by MOVPE on semi-insulating InP substrates. The epitaxial layer structure involves an In-rich channel achieving room temperature mobilities of 8,300 cm2/Vs. The fabrication of 100 nm T-Gate HEMTs gives rise to the highest reported fT = 256 GHz and fMAX = 360 GHz for Al-free GaInP/GaInAs InP pHEMTs. DC characterization yields shows saturation currents < 400 mA/mm and a maximum transconductance of 640 mS/mm.