Heavily Doped Channel Carrier Mobility in β-Ga2O3 Lateral Accumulation MOSFET

High critical field ( $\textit{E}_{{{\textit{c}}}}$ ) and low specific ON-resistance ( $\textit{R}_{\text{ON}}$ ) $\beta$ -Ga $_{{\text{2}}}$ O $_{{\text{3}}}$ devices such as accumulation channel metal-oxide-semiconductor field-effect-transistors (MOSFET) have been reported for high-power and extreme environment applications. Channel carrier mobility is a critical factor to reduce $\textit{R}_{\text{ON}}$ , but a lack of studies on channel mobility in $\beta$ -Ga $_{{\text{2}}}$ O $_{{\text{3}}}$ MOSFETs hinders understanding the electrical characteristics. We study carrier mobility in the channels with various doping concentrations using MOS-gated Hall measurements. Our MOSFET achieves a record-high peak channel mobility ( $\mu_{\text{peak}}$ ) of 143 cm $^{{\text{2}}}$ /V $\cdot$ s, to the best of our knowledge. Moreover, we suggest that further improvements can be made by enhancing Coulomb scattering-limited mobility ( $\mu_{{\textit{C}}}$ ).