Process Technology study of TiN/AlGaN/GaN Schottky contact on (111) Silicon substrate

Progress in high electron mobility transistors (HEMTs) based GaN, make them relevant candidates for high power devices with high frequency applications. However there are some issues to be solved for the improvement of this kind of heterostructures. In this paper, we report on a process to realize TiN/Au contacts grown by magnetron sputtering on AlGaN/GaN Si(111) heterostructures-passivated or no. We will present a study on the adequate surface treatment to use before the passivation and thermal annealing. The electrical behavior of rectifier contact was found to be changed by these treatments. The adequate thickness of the TiN layer will also be determined. Reduction of the gate leakage current by as much as six orders of magnitude was recorded by optimization of the thickness of TiN layer associated to a high barrier height.