High performance submicron inversion-type enhancement-mode InGaAs MOSFETs with ALD Al2O3, HfO2 and HfAlO as gate dielectrics

High-performance inversion-type enhancement-mode n-channel In
_0.53
Ga
_0.47
As MOSFETs with atomic layer deposited (ALD) Al
₂
O
₃
, HfO
₂
, and HfAlO as gate dielectrics are demonstrated. The ALD process on III-V compound semiconductors enables the formation of high-quality gate oxides and unpinning of Fermi level on III-V in general. A 0.5-mum gate-length MOSFET with an Al
₂
O
₃
gate oxide thickness of 8 nm shows a maximum drain current of 430 mA/mm and a transconductance of 160 mA/mm at drain voltage of 2 V. The transconductance is improved to 180 mA/mm by implementing HfO
₂
or HfAlO as gate dielectrics with the same oxide thickness. The peak effective mobility is -1200 cm
²
/Vs from dc measurement, ~ 4000 cm
²
/Vs after interface trap correction for HfO
₂
/In
_0.53
Ga
_0.47
As NMOSFETs.