RHEED patterns have been observed for vicinal surfaces of Si(001) and Si(111) polished into vicinal angle α = 2.5o and 3.1o, respectively. It was confirmed that both the glancing angle θ and the vicinal angle α can be estimated by the geometric relation between the diffraction spots and Kikuchi lines. For the step down incidence, bulk information such as Kikuchi lines and diffraction spots arisen from the three dimensional crystal lattices is mainly obtained. For the step up incidence, on the contrary, surface properties such as fractional order spots arisen from surface super structure is mainly obtained. In this study, features of the RHEED patterns taken from the vicinal surface are summarized and compared with calculated ones. It is concluded that these features can be explained by the escape length of electrons and the shadow effect by the step edges.
