High thermal stability of GaN schottky diode with Diamond-Like Carbon (DLC) anode design

High breakdown voltage and thermally stable AlGaN/GaN Schottky barrier diodes (SBDs) were fabricated using diamond-like carbon (DLC) anode design on a silicon (111) substrate. The DLC metal-hydrocarbon target in this study is tungsten-carbide and this film coating was prepared by reactive DC magnetron sputtering in a high temperature chamber. Based on the measured Raman spectrum, a broad peak with two shoulders at approximately 1365 cm^-1 (D peak) and 1570 cm^-1 (G peak) can be observed and the intensity of D peak versus G peak for DLC in this study is about 1.37 by considering both coefficient of thermal expansion and conductivity. The lower serial resistance was observed in Ni/DLC anode SBD and this characteristic was concluded that the junction heat during high current operation was dissipated through the surface DLC anode immediately and thus the thermal accumulation induced resistance was improved. Temperature dependent low frequency noise (LFN) and reverse recovery measurements both indicated that the Ni/DLC anode design exhibited a highly potential for being operated at high switching frequencies and high temperatures with low switching loss.