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

High critical field ( <tex-math notation="LaTeX">E_c</tex-math> ) and low specific ON-resistance ( <tex-math notation="LaTeX">RON</tex-math> ) <tex-math notation="LaTeX">β</tex-math> -Ga <tex-math notation="LaTeX">_2</tex-math> O <tex-math notation="LaTeX">_3</tex-math> 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 <tex-math notation="LaTeX">RON</tex-math> , but a lack of studies on channel mobility in <tex-math notation="LaTeX">β</tex-math> -Ga <tex-math notation="LaTeX">_2</tex-math> O <tex-math notation="LaTeX">_3</tex-math> 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 ( <tex-math notation="LaTeX">μₚₑₐₖ</tex-math> ) of 143 cm <tex-math notation="LaTeX">^2</tex-math> /V <tex-math notation="LaTeX">·</tex-math> s, to the best of our knowledge. Moreover, we suggest that further improvements can be made by enhancing Coulomb scattering-limited mobility ( <tex-math notation="LaTeX">μ_C</tex-math> ).