X-ray diffraction from low-temperature-grown silicon films with small surface roughness

Silicon films were grown by molecular beam epitaxy (MBE) at temperatures below 350 degrees C. The X-ray diffraction peaks from the (220) plane were observed only in the films grown at 300 degrees C and 250 degrees C, although they were not observed in the films grown above 350 degrees C and below 200 degrees C. The microroughness of the surface of the film was also examined by reflection high-energy electron diffraction (RHEED) and atomic force microscopy (AFM). The relationship between the X-ray diffraction peak from the (220) plane and the microroughness of the surface of the film are discussed.