Influence of process conditions on the electrical and optical properties of RF magnetron sputtered MoS₂films

Electrical transport and optical properties of magnetron sputtered MoS 2 films have been investigated as a function of process conditions. The results for the as-sputtered films and the influence of thermal annealing have been discussed in relation to the specific film morphologies and their inherent grain boundaries. Electrical resistivity measurements (300-10K) have shown that the substrate temperature (T s ) is the dominant sputtering parameter. At room temperature the resistivity varied between 3.8*10 -2 Omega cm (T s =-70 degrees C) and 10.1 Omega cm (T s =150 degrees C). Hall effect measurements indicated very low Hall mobilities (1-5 cm 2 V -1 s -1 at 297K). A check of the thermoelectric power response showed that for both the as-sputtered and annealed films the majority charge carriers are electrons. From optical absorption measurements an energy gap of 1.17 eV has been determined. In contrast to the electrical transport results, the optical properties were weakly influenced by process conditions.