Effect of post annealing treatments on the characteristics of ohmic contacts to n-type InN

To date, little work has been done regarding the annealing temperature and time dependence of contact resistance and contact intermixing on InN. In order to continue to improve for potential applications in photovoltaic devices, including high efficiency thin film solar cells, thermally stable ohmic contacts is required. To employ metal layers as a reliable ohmic contact on InN, it is essential to understand the thermal stability of metal-InN contact in addition to developing low resistance ohmic system. In this work, the structure of the InN films has been determined by means of conventional XRD phase analysis (omega/2 theta scan. Different annealing temperatures (400 degrees C-700 degrees C) and durations (1-30 minutes) of Ni/Ag metal contacts are investigated, as thermally stable metal-semiconductor contacts are essential for high quality devices. Specific contact resistivity, p, (SCR) determined using transmission line method (TLM) is carried out to the annealed (Ni/Ag) contacts where the electrical behavior of each of these conditions are compared. For relatively different annealing temperatures, substantial difference of the SCR values is observed between different durations samples.