The impact of the surface treatments on the properties of GaN/3C-SiC/Si based Schottky Barrier Diodes

In this work, we studied the Ti, Mo, and Ni Schottky contacts on N-GaN/SiC/Si substrates. The effect of surface preparation and substrate temperature during sputter deposition of Schottky contacts have been investigated. For the Ti Schottky, the substrate temperature of 100 degrees C during the sputtering demonstrates the minimum series resistance with Rs about 0.04 Omega cm(2), while temperatures greater than 300 degrees C increased reverse bias leakage. The Mott-Schottky plot reveals a barrier height of 1.2V for this Ti Schottky contact. Results for sputtered Ni contacts using different substrate temperatures demonstrate the some reverse bias leakages. We characterized the I-V curves of the Ni contact to investigate the effect of the Ar sputter cleaning before contact deposition. It demonstrates the Ar sputtering increases the reverse bias leakage and forward current. The Mo Schottky contact obtained at 100 degrees C without Ar cleaning shows a promising reverse bias leakage current and a fair forward bias current.