Submicrometer inversion-type enhancement-mode InGaAs MOSFET with atomic-layer-deposited Al2O3 as gate dielectric

Y Xuan, Purdue University
Y Q. Wu, Purdue University
H C. Lin, Purdue University
T Shen, Purdue University
P. D. Ye, Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University

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High-performance inversion-type enhancement-mode n-channel In0.53Ga0.47As MOSFETs with atomiclayer-deposited (ALD) Al2O3 as gate dielectric are demonstrated. The ALD process on III-V compound semiconductors enables the formation of high-quality gate oxides and unpinning of Fermi level on compound semiconductors in general. A 0.5-mu m gate-length MOSFET with an Al2O3 gate oxide thickness of 8 nm shows a gate leakage current less than 10(-4) A/cm(2) at 3-V gate bias, a threshold voltage of 0.25 V, a maximum drain current of 367 mA/mm, and a transconductance of 130 mS/mm at drain voltage of 2 V. The midgap interface trap density of regrown Al2O3 on In0.53Ga0.47As is similar to 1.4 x 10(12)/cm(2). eV which is determined by low- and high-frequency capacitance-voltage method. The peak effective mobility is similar to 1100 cm(2)/V . s from dc measurement, similar to 2200 cm(2)/V. s after interface trap correction, and with about a factor of two to three higher than Si universal mobility in the range of 0.5-1.0-MV/cm effective electric field.