Effective Suppression of MIS Interface Defects Using Boron Nitride toward High-Performance Ta-Doped-β-Ga2O3 MISFETs

: beta-Ga2O3 is considered an attractive candidate for next-generation high-power electronics due to its large band gap of 4.9 eV and high breakdown electrical field of 8 MV/cm. However, the relatively low carrier concentration and low electron mobility in the beta-Ga2O3-based device limit its application. Herein, the highquality beta-Ga2O3 single crystal with high doping concentration of similar to 3.2 x 1019 cm-3 was realized using an optical float-zone method through Ta doping. In contrast to the SiO2/beta-Ga2O3 gate stack structure, we used hexagonal boron nitride as the gate insulator, which is sufficient to suppress the metal-insulator-semiconductor (MIS) interface defects of the beta-Ga2O3-based MIS field-effect transistors (FETs), exhibiting outstanding performances with a low specific on-resistance of similar to 6.3 m Omega middotcm2 , a high current on/off ratio of similar to 108 , and a high mobility of similar to 91.0 cm2 /(V s). Our findings offer a unique perspective to fabricate high-performance beta Ga2O3 FETs for next-generation high-power nanoelectronic applications

Automated summary

β-Ga2O3 is considered a promising material for high-power electronics due to its large band gap and high breakdown electrical field. However, its low carrier concentration and electron mobility have limited its application. In this study, high-quality β-Ga2O3 single crystals with high doping concentration were successfully fabricated using an optical float-zone method with tantalum doping. By using hexagonal boron nitride as the gate insulator, the metal-insulator-semiconductor interface defects of β-Ga2O3-based field-effect transistors were suppressed, resulting in excellent performances.