High-performance self-aligned InAs MOSFETs with L-shaped Ni-epilayer alloyed source/drain contact for future low-power RF applications

In this study, InAs metal-oxide-semiconductor field effect transistors (MOSFETs) ultra-thin body (UTB) were fabricated with self-aligned method. 4 nm thick Al
2
O
3
gate oxide was deposited by Atomic Layer Deposition (ALD) technique. Ni-alloyed ohmic contacts for n-type source and drain (S/D) regions were formed at low annealing temperature (250°C). For a MOSFET with a gate length (L
G
) of 150 nm, we obtained a maximum drain current (Ion) of 700 mA/mm, and the extrinsic transconductance (G
M
, max) showed a peak value of 500 mS/mm. The devices exhibited a current gain cutoff frequency f
T
of 100 GHz and maximum oscillation frequency f
MAX
of 60 GHz for drain to source voltage (V
DS
) of 0.7 V.