Fig. 1. (Color online) (a) Cross-sectional view of the proposed NiO/β-Ga₂O₃ HJ-FET and the main fabrication process flows. Schematic representation of the testing method for the analysis instability under NBS at (b) single pulse, and (c) multiple pulses with a prolonged t_s.

Fig. 2. (Color online) Measured DC characteristics: (a) log-scale transfer characteristics and (b) output characteristics.

Fig. 3. (Color online) Measured (a) V_GS-I_DS and (b) V_GS-I_GS curves after NBS as a function of t_r. Extracted (c) ∆V_TH and (d) I_{GS, off} degradation ratio.

Fig. 4. (Color online) Measured (a) V_GS-I_DS and (b) V_GS-I_GS curves after NBS as a function of t_r. Extracted (c) ∆V_TH and (d) I_{GS, off} degradation ratio.

Fig. 5. (Color online) (a) Measured V_GS-I_DS curves during NBS at V_G,s = -20 V. (b) Extracted ∆V_TH.

Fig. 6. (Color online) Schematic cross-sections of NiO/β-Ga₂O₃ HJ-FET (a) at initial, (b) under NBS, and (c) after NBS, respectively.