The structure of polycrystalline Si (poly‐Si) films, prepared by annealing amorphous Si (a‐Si) films deposited using Si2H6, has been investigated by x‐ray diffraction (XRD), Raman scattering, transmission electron microscopy (TEM), and electron spin resonance, as functions of deposition conditions, such as deposition temperatureTd(450–580 °C) of thea‐Si and annealing time under a fixed temperature of 600 °C. A dominant texture of the poly‐Si films changed from a ⟨100⟩ texture forTdbelow 530 °C to a ⟨111⟩ forTdabove 530 °C, independent of the deposition rate of thea‐Si films and of the film thickness. Although the XRD grain size was independent ofTd, the TEM grain size increased from 1.0 to 2.5 &mgr;m with decreasingTd. It is suggested that the increase in this TEM size is caused by enhanced lateral growth of ⟨100⟩ grains due to the presence of strain. The spin densityNsand the factorgwere found to first increase with the annealing time, and rapidly decreased after the films were crystallized. It is also found that the value ofgfor the poly‐Si films decreased from 2.0051 to 2.0048 with decreasingTd. Furthermore, effects of post‐hydrogenation on the poly‐Si films with different textures were investigated, and a structural change of the boundary regions in the poly‐Si films is discussed in connection with a change in the dominant texture, through the corresponding change ing. ©1995 American Institute of Physics.