Enhancement-Mode Ga2O3 FET With High Mobility Using p-Type SnO Heterojunction

Mechanically exfoliated gallium oxide (Ga ₂ O ₃ ) nano sheets based filed-effect-transistors (FETs) with Al ₂ O ₃ /Ga ₂ O ₃ , indium gallium zinc oxide (IGZO)/Ga ₂ O ₃ n-n, and SnO/Ga ₂ O ₃ p-n heterojunctions in the back-channel were fabricated. In contrast to that Al ₂ O ₃ /Ga ₂ O ₃ heterojunction induces negative threshold voltage ( ${V} _{\text {TH}}$ ) shift, both IGZO/Ga ₂ O ₃ n-n and SnO/Ga ₂ O ₃ p-n heterojunctions shift ${V} _{\text {TH}}$ positively. The Ga ₂ O ₃ FET with 12 nm p-type SnO realizes enhanced-mode operation with ${V} _{\text {TH}}$ of 5.3 V by significantly shifting ${V} _{\text {TH}}$ of 40.3 V, high on current density of 14.1mA/mm, and high electron mobility of 191 cm ² V ⁻¹ s ⁻¹ , which is, to the best of our knowledge, the highest among the reported Ga ₂ O ₃ FETs measured at room temperature.