Physics-based numerical modeling and characterization of 6H-silicon-carbide metal–oxide–semiconductor field-effect transistors

Abstract

A detailed analysis of silicon-carbide (SiC) metal–oxide–semiconductor field-effect-transistor (MOSFET) physics is performed. Measurements of current–voltage characteristics are taken. A device simulator is developed based on the drift–diffusion equations. The model accounts for incomplete ionization. Comprehensive mobility and interface state models are developed for SiC MOSFETs. The mobility model accounts explicitly for bulk transport, as well as for interface states, surface phonons and surface roughness. Agreement between simulated and measured terminal characteristics is obtained. The results provide values for interface state occupation as a function of energy and position along the surface. Results giving values for surface mobility as a function of position along the channel indicate that interface states have an especially strong effect on SiC operation. Our investigation indicates that substantial reduction of interface states can give rise to a fivefold increase in transconductance.

Electrical Characteristics of SiO2 Deposited by Atomic Layer Deposition on 4H–SiC After Nitrous Oxide Anneal

“…Based on Matthiessen's rule, the mobility component associated with the strongest scattering mechanism dominates the total low-field mobility [19]. It is shown that the Coulomb mobility increases with the device operating temperature, whereas the bulk and surface phonon mobility components decrease with temperature, and the surface roughness mobility does not have any explicit temperature dependence [19]. Therefore, if higher mobility is observed at elevated temperatures, the mobility is limited by the Coulomb scattering as seen in typical Si-face SiC devices with thermally grown SiO 2 [19].…”

High Mobility 4H-SiC Lateral MOSFETs Using Lanthanum Silicate and Atomic Layer Deposited SiO₂

“…4(a), from room temperature to 200°C, the peak mobility without LaSiO x increases slightly, which suggests that the electron mobility of this device is limited by coulombic scattering associated with trapped D it and fixed oxide charges [12]. In contrast, it is observed that the peak mobility of the device with LaSiO x reduces at elevated temperatures confirming that the La containing device's mobility is limited by phonon scattering instead of coulombic scattering.…”

“…Based on Matthiessen's rule, the lowest mobility component limits the total low field mobility and thus the corresponding scattering process dominates [12]. It is well known that the bulk and surface phonon mobility decrease with measurement temperature, whereas coulombic mobility increases with temperature and the surface roughness mobility does not have explicit temperature dependence [12]. Therefore, if higher peak mobility is observed at elevated temperatures, the mobility is dominated by the coulombic scattering.…”

Modeling and experimental study of MOS channel mobility of etched GaN on silicon substrate

“…The Hall mobilities were then modelled using physics based model, in which the total mobility is limited by the bulk mobility μ B , surface phonon scattering μ SP , surface roughness μ SR , and Columbic scattering μ Cit [3].…”