A Comprehensive Benchmarking Method for the Net Combination of Mobility Enhancement and Density-of-States Bottleneck

Abstract

benchmarking method to simultaneously address mobility enhancement and density-of-states bottleneck in advanced field-effect-transistors (FETs) with novel highmobility (high-μ) channel materials, where we focused on conventional covalent bonding semiconductors with pure and partially ionic character. This method relies only on themeasured extrinsic transconductanceof a long-channel FET in the saturation regime together with the source resistance, yielding the product of the effective mobility (μeff ) and effective gate capacitance (Cg_eff ). We tested this method in InxGa1?xAs quantum-well high-electron-mobility transistors (HEMTs) with various indium mole fractions, such as 0.53, 0.7, 0.8 and 1, aswell as in Si n-FETs.We found that the InxGa1?xAs HEMTs with μeff over 10,000 cm2/V·s at 300 K provided more than 20 times greater μeff× Cg_eff than Si n-FETs. More specifically, the product initially improved as x increased, then showed a peak value of 10,300 μF·V?1·s?1 at x of around 0.8, and degraded slightly beyond that composition. To verify the validness of the proposedmethod, we separatelymeasured and analyzedCg_eff and μeff using the split-CV technique, showing excellent agreement with the ones from the proposed method.