Fig. 1. (Color online) (a) Schematic of the first field-plated β-Ga₂O₃ SBD. (b) Forward current–voltage (I–V) characteristic of the device. (c) Reverse breakdown characteristic of the device. Reprinted from Ref. [21], with the permission of AIP Publishing.

Fig. 2. (Color online) (a) Schematic of a β-Ga₂O₃ SBD with an ultrahigh-permittivity field-plate dielectric, where S1 corresponds to a 15-period BaTiO₃/SrTiO₃ superlattice as the field-plate oxide [(BTO/STO)₁₅ FP] and S2 corresponds to BaTiO₃ as the field-plate oxide (BTO FP). The cross-sectional transmission electron microscopy image depicts the field-plated region of the S1 structure. (b) Forward I–V characteristics and differential R_ON,sp of a β-Ga₂O₃ SBD with (BTO/STO)₁₅ FP, a β-Ga₂O₃ SBD with BTO FP, and a reference SBD without a field plate. (c) Reverse breakdown characteristics of the three different SBD structures. © 2021 IEEE. Reprinted, with permission, from Ref. [40].

Fig. 3. (Color online) (a) Schematics of beveled-mesa β-Ga₂O₃ SBDs with a ~45° beveled field plate (BFP) and with a small-angle (~1°) beveled field plate (SABFP). (b) Reverse breakdown characteristics of the BFP-SBD and SABFP-SBD showing higher V_br than those of mesa-free β-Ga₂O₃ SBDs that are either unterminated or terminated with a ~45° beveled surface field plate (SFP). (c) Forward I–V characteristics and differential R_ON,sp of SABFP-SBDs with different anode diameters. © 2019 IEEE. Reprinted, with permission, from Ref. [44].

Fig. 4. (Color online) Comparison between reverse breakdown characteristics of β-Ga₂O₃ SBDs with no edge termination, He-implanted edge termination, and Mg-implanted edge termination. © 2020 IEEE. Reprinted, with permission, from Ref. [45].

Fig. 5. (Color online) Schematics of an unterminated β-Ga₂O₃ SBD, a β-Ga₂O₃ SBD with self-aligned fluorine plasma treatment (FPT), and a β-Ga₂O₃ SBD with self-aligned beveled fluorine plasma treatment (BFPT). (b) Forward I–V characteristics and differential R_ON,sp of the three different SBDs. (c) Reverse breakdown characteristics of the three different SBDs. © 2020 IEEE. Reprinted, with permission, from Ref. [57].

Fig. 6. (Color online) Schematic of a β-Ga₂O₃ SBD terminated with p-NiO FLRs alongside an unterminated device. Reprinted from Ref. [63], with the permission of AIP Publishing.

Fig. 7. Calculated maximum surface electric fields (E_surf) in β-Ga₂O₃ SBDs, defined at a maximum reverse leakage current (J_R,max) of 1 or 100 mA/cm² at 25 °C. Experimental data from the literature are also shown (solid for J_R,max = 1 mA/cm² and hollow for J_R,max = 100 mA/cm²). Adapted from Ref. [67], with the permission of AIP Publishing.

Fig. 8. (Color online) (a) Schematic of the first β-Ga₂O₃ JBSD. (b) Forward I–V characteristic of the JBSD showing similar V_ON to a regular β-Ga₂O₃ SBD and lower V_ON than a p-NiO/n-Ga₂O₃ diode (PND). (c) Reverse breakdown characteristic of the JBSD showing higher V_br than a regular β-Ga₂O₃ SBD because of the RESURF effect but lower V_br than a PND owing to higher reverse leakage current through a Schottky junction. Reprinted with permission from Ref. [72]. Copyright 2019 SPIE.

Fig. 9. (Color online) (a) Schematic of a field-plated β-Ga₂O₃ trench SBD. (b) Cross-sectional scanning electron microscopy image of a fin channel. (c) Reverse breakdown characteristics of field-plated β-Ga₂O₃ trench SBDs. In comparison with regular β-Ga₂O₃ SBDs employing both mesa and field plate terminations, the field-plated trench devices have much lower leakage current and a much higher V_br. (d) Forward I–V characteristics and differential R_ON,sp of field-plated β-Ga₂O₃ trench SBDs under DC and pulsed conditions. A base voltage of 0 V, a pulse width of 1 µs, and a duty cycle of 0.1% are used for the pulsed measurements. © 2020 IEEE. Reprinted, with permission, from Ref. [82].

Fig. 10. (Color online) Simulated electric-field profiles in a β-Ga₂O₃ trench SBD along a vertical cutline at the center of a fin under a reverse bias of –1375 V by varying (a) fin width [W_fin, see Fig. 9(a)] and (b) trench depth [d_tr, see Fig. 9(a)]. © 2020 IEEE. Reprinted, with permission, from Ref. [83].

Fig. 11. (Color online) (a) Schematic of a field-plated β-Ga₂O₃ SBD with double-side-cooling flip-chip package. (b) I–V waveforms of the double-side-cooled device in surge current tests. (c) I–V loops of the double-side-cooled device. © 2021 IEEE. Reprinted, with permission, from Ref. [90].