Impact of Device Parameters on the Performance of β-Ga2O3 Nanomembrane MESFETs

In this study, we have systematically investigated the impact of intrinsic device parameters on the performance of beta gallium oxide (
$\beta $
-Ga2O3) nanomembrane metal–semiconductor field effect transistors (NM-MESFETs). The ON- and OFF-state performances of these devices were analyzed using a well-calibrated technology computer-aided design (TCAD) simulator, focusing on breakdown voltage
${(} {V}_{\text {BR}} {)}$
, ON-resistance (
${R}_{\text {ON}}{)}$
, threshold voltage
${(} {V}_{\text {th}} {)}$
, maximum drain current
${(} {I}_{\text {D},\text {max}} {)}$
, and power figure of merit
${(} \text {PFOM} {)}$
. Two distinct breakdown mechanisms are identified, significantly affecting
${V}_{\text {BR}}$
of these NM-MESFETs. Interestingly, when studying the effect of individual device parameters on
${V}_{\text {BR}}$
, we observed an initial increasing trend up to a critical value, followed by a sharp fall and a subsequent decreasing trend. Through simulations, an empirical model is developed that facilitates the selection of appropriate device parameters to achieve MESFETs with high
${V}_{\text {BR}}$
. In addition, an analytical model of
${V}_{\text {th}}$
of the MESFET in terms of its device parameters is also proposed and validated with simulation results. The performance of the NM devices is also benchmarked against reported Ga2O3 devices.