AlGaN/GaN Schottky Diode Fabricated by Au Free Process

An AlGaN/GaN Schottky diode is fabricated using an Au free process. Both ohmic and Schottky contact are studied. The ohmic contact results show low contact resistance and good surface morphology. The specific resistance (ρc) and contact resistance (Rc) of the ohmic contact are ~ 3.5×10-5Ω×cm2and 2.1 Ω·mm, respectively. Several current transport mechanisms are employed to analyze the measured I- V curves of the diode. The data have demonstrated that at a lower forward bias the combination of generation recombination and tunneling current mechanisms are dominant, whereas the thermionic emission mechanism becomes more significant at a higher forward bias. The effective Schottky barrier height is estimated to be 0.99 eV. The breakdown voltage of AlGaN/GaN Schottky diode is ~ 125 V.