Impact of Quantum Capacitance on Intrinsic Inversion Capacitance Characteristics and Inversion-Charge Loss for Multigate III-V-on-Insulator nMOSFETs

This paper investigates the impact of quantum capacitance on the intrinsic inversion-capacitance (C inv ) characteristics of high-mobility multigate III-V-on-insulator nMOSFETs through a numerical simulation corroborated by the theoretical calculation. Nonmonotonic C inv characteristics stemming from the energy dependence of 1-D density-of-states and significant C inv degradation due to quantum capacitance have been found in trigate In 0.53 Ga 0.47 As and InAs devices based on the ITRS 2018-2024 technology nodes. This paper indicates that, to compensate the excess inversion-charge (Q inv ) loss due to quantum capacitance, the needed mobility gain of the trigate InGaAs and InAs devices (against the Si counterparts) should be at least ~3× and ~4×, respectively. This paper also suggests that the quantum-capacitance-induced Q inv loss can be mitigated by raising the fin aspect ratio of the III-V multigate device.