100nm Gate length enhancement-mode In0.4Ga0.6As MOSFETs with InGaP interfacial layer and Al2O3 as gate oxide

An enhancement-mode implant-free In0.4Ga0.6As metal oxide semiconductor field effect transistors (MOSFETs) on GaAs substrate is demonstrated. The device features atomic layer deposition (ALD) 8 nm Al2O3 gate oxide layer on 5 nm InGaP interfacial layer and is fabricated on GaAs substrate. Devices with 100 nm gate-length exhibit a threshold voltage of 0.72 V, an extrinsic transconductance of 170 mS/mm, and a saturation drain current of 250 mA/mm. The current gain cutoff frequency, fT, and the maximum frequency of oscillation, fmax, of 79 GHz and 180 GHz were obtained, respectively. This work suggests that InGaAs MOSFETs with InGaP interfacial layer on GaAs can be used in single power supply RF applications.