Metal-semiconductor contacts to n-ZnS_0.07Se_0.93

A systematic study was conducted on electrical properties of metal-semiconductor contacts to n-ZnS_0.07Se_0.93 with metals of different metal work functions. A clear relation was found between the Schottky barrier height and the metal work function although the Schottky contact theory could not predict it accurately. Thermionic-emission was found to be the dominant current transport mechanism. A significant Schottky barrier height improvement was achieved by means of a cryogenic process technique for forming the Au/n-ZnS_0.07Se_0.93 contact. A thermal stability study was also conducted on Pd and Au/n-ZnS_0.07Se_0.93 contacts. Thermal annealing tests showed a stable electrical property up to T = 250°C for the Pd contact and T = 150°C for the Au contact, however, a dramatic degradation was observed after higher temperature annealing and this is attributed to the interaction between metals and ZnSSe after annealing as supported by Auger electron spectroscopy.