In this paper, we have fabricated and characterized In0.7Ga0.3As quantum-well (QW) metaloxide-semiconductor field-effect-transistors (MOSFETs). We have employed the gate dielectric of the Al2O3/HfO2 (0.6/2 nm) bi-layer stack by ALD. The fabricated device with L-g = 4 mu m exhibits a record maximum transconductance (g(m_max)) in excess of 520 mu S/mu m at > 1 mu m region, and reasonably good electrostatic integrity, such as SS = 110 mV/decade and DIBL = 43 mV/V. Also, we have investigated the gate length scaling behavior in terms of output, transconductance, and transfer characteristics. In particular, our devices feature very uniform values of the electrostatic integrity, such as SS = 100-110 mV/decade, V-T = -0.25 V to -0.2 V and DIBL = 40-50 mV/V, as L-g decreases from 10 mu m to 4 mu m. Furthermore, we have explored the impact of source resistance (R-S) onto the device characteristics of the InGaAs QW MOSFETs. In doing so, we have modeled both measured extrinsic transconductance (g(m_ext)) and intrinsic transconductance (g(m_int)) as a function of L-g. (C) 2016 Elsevier Ltd. All rights reserved.