Enlargement of grain size for MoS2 film fabricated by RF magnetron sputtering with additional DC bias by optimization of deposition parameters and its evaluation with Raman spectroscopy

Abstract

Raman spectroscopy was used to evaluate crystal quality of MoS2 films fabricated by RF magnetron sputtering with additional DC bias. Raman spectroscopy is a powerful tool to evaluate different physical properties of a film since phonons are sensitive to those properties. From the results of Raman spectroscopy measurements, improvement of crystal quality was shown corresponding to increase of the DC bias voltage, increase in the substrate temperature, and decrease of the deposition rate. Furthermore, the grain size was quantitatively evaluated by using the frequency deference between E12g and A1g Raman peaks. Through these evaluation it was revealed that the sputter parameter adjustment listed above (increase in DC bias voltage, etc.) increased grain size showing the film quality improvement quantitatively. Therefore, optimization of these sputtering parameters contributes to the fabrication of high quality MoS2 film at low-temperature.