FIG. 1.5 (a) Triangular electric field profile in a Schottky diode ( Baliga, 2009 ). (b) WBG and UWBG devices require less depletion width (and hence device size) to withstand the same breakdown voltage due to their high breakdown field. More about this image found in (a) Triangular electric field profile in a Schottky diode ( Baliga, 2009 )....

FIG. 1.13 Schematic of basic Schottky diode structures from MOCVD-grown β-Ga₂O₃ (a) vertical diode and (b) lateral diode. Reproduced with permission from Zhang et al., APL Mater. 7 (2), 022506 ( 2019 ). Copyright 2019 AIP Publishing LLC. More about this image found in Schematic of basic Schottky diode structures from MOCVD-grown β-Ga₂...

FIG. 1.16 (a) Vertical β-Ga₂O₃ Schottky diodes with field plate, (b) corresponding electric field profile showing the peak field (in red) redistributed by field plate ( Konishi et al., 2017 ), and (c) bevel field plate Schottky diodes with sidewall angles of 55.7° ( Joishi et al., 2018 ). More about this image found in (a) Vertical β-Ga₂O₃ Schottky diodes with field plate...

FIG. 1.18 (a) Simulated electric field profile of the Trench Schottky barrier diode at breakdown voltage of 2.89 kV. (b) The electric field profile along cutline-1 shows that the peak field of 5.6 MV/cm appears at trench corners. (c) Electric field profile along the fin center (cutline 2) shows that the high electric field appears at the trench depth, d_tr = 1.1 µm, whereas the near Schottky contact regions experience a reduced surface electric field of E_surf = 0.7 MV/cm. Cutline 3 along the trench center also shows the maximum electric field located at the trench depth ( Li et al., 2021 ). More about this image found in (a) Simulated electric field profile of the Trench Schottky barrier diode a...

FIG. 8.2 Equipotential contours of a reverse-biased Schottky diode showing 2-D field crowding at the edge of the Schottky contact. More about this image found in Equipotential contours of a reverse-biased Schottky diode showing 2-D field...

FIG. 13.2 State-of-the-art SiC, GaN and Ga₂O₃ Schottky Barrier Diode (SBD) performance. Specific on-resistance R_on,sp and V_f normalized to area are plotted for each semiconductor. The dashed lines represent the R_on,sp vs breakdown voltage theoretical limit for each material ( Bhatnagar et al., 1992 ; Takatsuka et al., 2018 ; Lin et al., 2019 ; Lynch et al., 2019 ; Xiao et al., 2020 , 2021 ; Roy et al., 2021 ; Dong et al., 2022 ; Kumar et al., 2022 ; and Zhang et al., 2022 ). More about this image found in State-of-the-art SiC, GaN and Ga₂O₃ Schottky Barrier ...

FIG. 1.17 Device schematic and surface electric field (E_surf) along the vertical cutline (E_y) at the center of the anode contact for β-Ga₂O₃ (a) Regular Schottky diode and (b) Trench Schottky barrier diode ( Li et al., 2021 ). (c) Reverse bias characteristics for a trench SBD with trench depth, d_tr = 1.55 µm and conventional SBD showing lower leakage current density and higher breakdown voltage achieved by trench SBD ( Li et al., 2021 ). More about this image found in Device schematic and surface electric field (E_surf...

FIG. 8.4 Schematic of an SBD with a single-step field plate with length L_FP and height h_FP connected to the Schottky electrode. The × and ∗ symbols indicate the positions of peak off-state electric fields, whose intensities are determined by both L_FP and h_FP. More about this image found in Schematic of an SBD with a single-step field plate with length L...

FIG. 8.23 (a) Schematic illustration of the RESURF effect in a trench SBD. Key geometric parameters controlling the RESURF effect are the trench depth (d_tr), fin width (W_fin), and trench width (W_tr). (b) Effect of d_tr in shaping the equipotential contours in the fin regions of a trench SBD, where the equipotential contours are stretched away from the Schottky interface with increasing d_tr. Two distinct advantages of this RESURF effect are a reduction in the electric field at the Schottky interface and a shift in the peak electric field from the surface into the bulk of the semiconductor. Reprinted with permission from Mehrotra and Baliga, IEEE International Electron Devices Meeting (IEDM), 5–8 December 1993 (IEEE, Washington, DC, USA, 1993), pp. 675–678. Copyright 1993 IEEE. More about this image found in (a) Schematic illustration of the RESURF effect in a trench SBD. Key geomet...

FIG. 1.22 Experimentally obtained maximum operating temperature vs maximum reverse breakdown voltage of Schottky diodes showing β-Ga₂O₃ devices can reach high-temperature and high-breakdown operation with simpler designs compared to SiC and GaN ( Wang et al., 2019 ). More about this image found in Experimentally obtained maximum operating temperature vs maximum reverse br...

FIG. 6.6 The deep donor level E_d2 at ∼E_C–0.12 eV (a) increases with Si doping in β-Ga₂O₃ ( Ghadi et al., 2020a ) and (b) associated effect of E_d2 level with an estimated increase of on-resistance due to incomplete ionization during forward bias operation of β-Ga₂O₃ Schottky diodes ( Neal et al., 2017 ). More about this image found in The deep donor level E_d2 at ∼

FIG. 8.26 Ideal, laterally homogeneous barrier height corrected for image-force lowering vs metal work function for (a) plain metals and (b) oxidized metal Schottky contacts on ( 2 ¯ 01) β-Ga₂O₃. Reprinted with permission from Hou et al., Appl. Phys. Lett. 114 (3), 033502 (2019a). Copyright 2019 AIP Publishing LLC. More about this image found in Ideal, laterally homogeneous barrier height corrected for image-force lower...

FIG. 1.15 (a) Field crowding at the contact edge in an n-type Schottky diode at reverse bias, and reduction of field crowding by field redistribution from corners using (b) field plate, (c) p-type guard ring. Reprinted with permission from Sun et al., Electronics  8 (5), 575 (2019). Copyright 2019 Author(s), licensed under Creative Commons Attribution 4.0 License, CC by http://creativecommons.org/licenses/by/4.0/ . More about this image found in (a) Field crowding at the contact edge in an n-type Schott...

FIG. 1.19 (a) MIS β-Ga₂O₃ diode with extreme-κ dielectric BaTiO₃, and the band profile at large reverse bias in (b) conventional Schottky diodes showing electron tunneling effects through thin triangular barrier (c) in BaTiO₃ MIS diodes showing that the flat conduction band profile in BaTiO₃ can effectively block tunneling electrons. The E_C, E_V, and E_f indicate the conduction band, valence band, and Fermi level in the band diagram, respectively ( Xia et al., 2019 ). More about this image found in (a) MIS β-Ga₂O₃ diode with extreme-κ dielectric BaTiO...

FIG. 8.22 (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 Sasaki et al., Proc. SPIE 10919 , 1091913 (2019). Copyright 2019 SPIE. More about this image found in (a) Schematic of the first β-Ga₂O₃ JBSD. (b) Forward ...