In situ X-ray reflectivity measurement of thin film growth during vacuum deposition

The X-ray reflectivity method was used to measure in situ the surface roughness of a thin film during growth. In this experiment, aluminum was deposited on the surface of a silicon wafer under a vacuum condition of 10−6 Torr. We found that the surface roughness increased as the film became thicker. A large growth exponent of β = 1 was obtained. The data were compared with the scaling behavior of the surface interfacial width that was theoretically predicted and experimentally verified for non-equilibrium growth conditions.