Submicrometer Inversion-Type Enhancement-Mode InGaAs MOSFET With Atomic-Layer-Deposited $\hbox{Al}_{2}\hbox{O}_{3}$ as Gate Dielectric

Y Xuan,Y Q Wu,Peide D Ye,H C Lin,T Shen

doi:10.1109/led.2007.906436

Abstract

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 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-mum gate-length MOSFET with an Al 2 O 3 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 Al 2 O 3 on In 0.53 Ga 0.47 As is ~1.4 x 10 12 /cm 2 ldr eV which is determined by low-and high-frequency capacitance-voltage method. The peak effective mobility is ~1100 cm 2 / V ldr s from dc measurement, ~2200 cm 2 / V ldr 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.

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