β-Ga[sub.2]O[sub.3] Schottky Barrier Diode with Ion Beam Sputter-Deposited Semi-Insulating Layer

• Published in: Crystals (Basel) 2024-01, Vol.14 (2)
• Main Authors: Yakovlev, Nikita N, Almaev, Aleksei V, Kushnarev, Bogdan O, Verkholetov, Maksim G, Poliakov, Maksim V, Zinovev, Mikhail M
• Format: Article
• Language: English
• Subjects: Chemical properties; Diodes, Schottky-barrier; Electric properties; Gallium compounds; Materials; Particle beams
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst14020123

Vertical Schottky barrier diodes based on an ion beam sputter (IBS)-deposited β-Ga[sub.2] O[sub.3] film on a single-crystalline (2¯01) unintentionally doped (UID) β-Ga[sub.2] O[sub.3] with a Ni contact were developed. To form ohmic Ti/Ni contacts, the IBS-Ga[sub.2] O[sub.3] /UID β-Ga[sub.2] O[sub.3] structures were wet-etched, and an indium tin oxide (ITO) intermediate semiconductor layer (ISL) was deposited on the opposite surface of the UID β-Ga[sub.2] O[sub.3] . The IBS-deposited Ga[sub.2] O[sub.3] layer was polycrystalline and semi-insulating. Low leakage currents, rectification ratios of 3.9 × 10[sup.8] arb. un. and 3.4 × 10[sup.6] arb. un., ideality factors of 1.43 and 1.24, Schottky barrier heights of 1.80 eV and 1.67 eV as well as breakdown voltages of 134 V and 180 V were achieved for diodes without and with ITO-ISL, respectively. The surface area of the IBS-Ga[sub.2] O[sub.3] film acted as a thin dielectric layer and, together with the preliminary wet etching, provided low leakage currents and relatively high Schottky barrier heights. Diodes with a Schottky barrier based on a Ni/IBS-deposited Ga[sub.2] O[sub.3] film contact were demonstrated for the first time.