Phase shift behavior of RHEED intensity oscillation in intermediate growth mode between layer-by-layer mode and step flow mode

Phase shift behavior of the first oscillation of reflection high-energy electron diffraction specular beam intensity was observed in the process of the resumption after growth interruption during epitaxial growth of SrTiO3 on SrTiO3 (001) substrate with the misorientation angle of 1°. The growth proceeded in intermediate mode between layer-by-layer mode and step flow mode. Using an exactly oriented substrate, the phase shift phenomena disappeared, when the growth was a perfect layer-by-layer mode. The phase shift appears to be closely related to the growth mode. This is the first observation of phase shift of intensity oscillation in the growth mode between 2D nucleation on the terraces and step propagation. By observing the period of the first oscillation, initial surface roughness on the substrate can be identified.