Modeling and Analysis of Gallium Oxide Vertical Transistors

Abstract

Gallium oxide (Ga2O3) based semiconductor devices are expected to disrupt power electronic applications in the near future. Due to the wide bandgap of Ga2O3, it should be possible to fabricate power devices with higher breakdown voltages and lower on-state resistances compared to incumbent Silicon (Si) and Silicon Carbide (SiC) technologies. In particular, vertical metal-oxide field effect transistor (MOSFETs) and vertical Fin Field Effect Transistor (FinFETs) devices based on Ga2O3 have been recently reported. Here, we present a comparative modelling study of such vertical Ga2O3 power transistors using use Technology Computer Aided Design (TCAD) and analyze their electro-thermal performance under static and dynamic operating conditions. We find that the MOSFETs show a trade-off between the current gains and threshold voltages, as a function of device geometry and acceptor concentrations in the body region. In contrast, in the FinFETs structures it is possible to achieve normally-off operation by proper design of the fin width and its donor concentration, without p-type doping. Overall, the modeling and analysis results presented here can be used as a guide for experimental improvement of the vertical Ga2O3 device performance for future power electronic applications.

Enhancement Mode Ga2O3 Field Effect Transistor with Local Thinning Channel Layer

“…TCAD provides an efficient way to understand the properties of the device. Up to now, many related works have been reported on the TCAD simulation of Ga 2 O 3 transistors [36][37][38]. Due to the non−convergence of the bottom gate model, we used a similar structure for the top gate to analyze the effect of the local thinning on the threshold voltage.…”

Current State of Ga2O3-Based Electronic and Optoelectronic Devices. Brief Review

“…So, Kotecha et al in ref. [118] simulated and analyzed a vertical MOSFET on -Ga 2 O 3 . The study showed an inverse relationship between the threshold voltage and the current amplification, and their dependence on the device geometry and the acceptor concentration in the crystal.…”

Electrothermal Modeling and Analysis of Gallium Oxide Power Switching Devices

“…Also, it has a very high breakdown field in the range of 8 MV/cm. With such superior material properties, the theoretical Baliga Figure of Merit is estimated to be close to 3,444, which is about 10 times higher than SiC and 5 times higher than GaN [6]- [9]. The biggest challenge with respect to the Ga2O3 material is its low thermal conductivity compared to SiC and GaN, which poses a significant challenge for its adoption in power electronics applications.…”