PtO_x Schottky Contacts on Degenerately Doped (2^-01)β-Ga₂O₃ Substrates

Platinum oxide (PtOx) Schottky contacts on degenerately doped beta-Ga2O3 substrates show an increased barrier height of 85% and 64% when compared to nickel and platinum Schottky contacts, respectively. At low reverse voltage bias, the reverse leakage current of the PtOx Schottky barrier diodes was approximately 5-6 orders of magnitude lower than the reference evaporated Ni and Pt Schottky contacts. PtOx Schottky contacts were deposited using reactive sputtering on highly doped (8 x 10(18) cm(-3)) (201) beta-Ga2O3:Sn substrates grown by the edge-defined film-fed growth (EFG) method. All Schottky metals were capped with evaporated Au. Capacitance-voltage and temperature-dependent current-voltage measurements were performed in order to extract the barrier height of the PtOx Schottky contact. Analysis of the diode ideality factors reveal that the PtOx Schottky contacts on highly doped beta-Ga2O3 do not follow the thermionic field emission model and are impacted by inhomogeneous barrier height distribution. This work highlights the significance of PtOx Schottky contacts for beta-Ga2O3-based power devices as a means for reducing leakage current. This work also holds relevance for low-voltage applications, where Schottky contacts for degenerately doped semiconductors can enable new electronic device applications.