Structural properties and surface topography of MgO films prepared on Si (100) by pulsed DC magnetron sputtering

This work deals with the preparation of MgO films on Si (100) substrate by using pulsed DC magnetron sputtering of pure Mg target in reactive oxygen environment at room temperature. The sputtering power was varied in the range 100 W to 150 W while keeping the deposition time fixed at 4 h. In the next step, deposition time was changed from 1 h to 3 h by maintaining the sputtering power at 150 W. The results obtained were analyzed by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) techniques. The XRD pattern at 100 W exhibited MgO2 diffraction peak along (211) plane. However, with increase of power to 125 W and 150 W, MgO diffraction peak corresponding to (200) plane appeared. The crystallinity of MgO was improved with increase of the sputtering power. On contrary, the crystalline quality of MgO film was degraded with increase of the deposition time. The FTIR analysis displayed peaks around 860 cm(-1) and 740 cm(-1) corresponding to the characteristic of cubic MgO. With increase of deposition time from 1 h to 3 h, the peaks at 860 cm(-1) and 740 cm(-1) were disappeared, indicating a decrease in the strength of chemical bond between Mg and O. The AFM results revealed a decrease in the surface roughness with increase of both sputtering power and the deposition time.