Minority-carrier characteristics of InGaAs metal-oxide-semiconductor structures using atomic-layer-deposited Al2O3 gate dielectric

Atomic layer deposition (ALD) provides a unique opportunity to integrate high-quality gate dielectrics on III-V compound semiconductors. ALD Al2O3 is a high-quality gate dielectric on III-V compound semiconductor with low interface trap density, low gate leakage, and high thermal stability. The authors study the minority-carrier response of Al2O3∕InGaAs metal-oxide-semiconductor (MOS) structures, which sheds light on the device physics for realizing high-performance inversion-type metal-oxide-semiconductor field-effect-transistor. The minority carriers in InGaAs do not respond to a small ac signal down to 100Hz at 300K, while they respond to up to 100kHz at 500K. Temperature dependent capacitance-voltage (C-V) measurement on the InGaAs MOS structure reveals the activation energy (Ea) of the minority-carrier recombination to be about 0.62eV.