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

An enhancement-mode implant-free In
_0.4
Ga
_0.6
As metal oxide semiconductor field effect transistors (MOSFETs) on GaAs substrate is demonstrated. The device features atomic layer deposition (ALD) 8 nm Al
₂
O
₃
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, f
_T
, and the maximum frequency of oscillation, f
_max
, 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.