600 V-18 A GaN Power MOS-HEMTs on 150 mm Si Substrates With Au-Free Electrodes

We present the development of an Au-free ohmic contact metallization for high voltage GaN-based high electron mobility transistors (HEMTs). In this letter, low contact resistance (0.81 Ω·mm) is obtained for Au-free electrodes on AlGaN/GaN HEMT structures. Using Au-free ohmic processes, large scale high power GaN metal-oxide-semiconductor HEMTs were successfully fabricated in a procedure fully compatible with standard Si CMOS manufacturing with the maximum drain current of more than 18 A and low OFF-state leakage current of 3×10^-7 A at VDS of 600 V. The practicality of the devices was further demonstrated by measurements of the current collapse effects under severe operating conditions and the temperature dependence of the electrical characteristics.