An Au-free GaN high electron mobility transistor with Ti/Al/W Ohmic metal structure

We demonstrate the Au-free GaN HEMT device with the Ti/Al/W Ohmic metal structure. Excellent surface roughness 4.88nm for Ti/Al/W Ohmic stucture was achieved after metallization. The DC characteristics is comparable with conventional HEMTs and the stress performance with high voltage is better than conventional HEMTs.