Reverse leakage mechanism of Schottky barrier diode fabricated on homoepitaxial GaN

In this work, Schottky barrier diodes with vertical geometry were fabricated on low-defect-density homoepitaxial GaN for studying the reverse leakage mechanism of GaN-based Schottky contact. A leakage current model based on electron transmission primarily through linear defects like dislocations was suggested to explain the reverse current–voltage characteristics measured between 300 and 410 K, in which electrons from contact metal overcome the locally height-reduced Schottky barrier through thermionic-field emission.

► Vertical Schottky diodes are fabricated on low-defect-density homoepitaxial GaN.
► The diode shows low leakage current on the order of ∼10−11 under −10 V bias.
► A leakage model based on electron transmission along linear defects are suggested.
► Electrons overcome the height-reduced Schottky barrier through TFE emission.