High performance lateral Schottky diodes based on quasi-degenerated Ga2O3

Ni/beta-Ga2O3 lateral Schottky barrier diodes (SBDs) were fabricated on a Sn-doped quasi-degenerate n(+)-Ga2O3 ((2) over bar 01) bulk substrate. The resultant diodes with an area of 7.85 x 10(-5) cm(2) exhibited excellent rectifying characteristics with an ideality factor of 1.21, a forward current density (J) of 127.4 A/cm(2) at 1.4 V, a specific on-state resistance (R-on,R-sp) of 1.54 m Omega.cm(2), and an ultra-high on/off ratio of 2.1 x 10(11) at perpendicular to 1 V. Due to a small depletion region in the highly-doped substrate, a breakdown feature was observed at -23 V, which corresponded to a breakdown field of 2.1 MV/cm and a power figure-of-merit (V-B(2)/R-on) of 3.4 x 10(5) W/cm(2). Forward current-voltage characteristics were described well by the thermionic emission theory while thermionic field emission and trap-assisted tunneling were the dominant transport mechanisms at low and high reverse biases, respectively, which was a result of the contribution of deep-level traps at the metal-semiconductor interface. The presence of interfacial traps also caused the difference in Schottky barrier heights of 1.31 eV and 1.64 eV respectively determined by current-voltage and capacitance-voltage characteristics. With reduced trapping effect and incorporation of drift layers, the beta-Ga2O3 SBDs could further provide promising materials for delivering both high current output and high breakdown voltage.