Undoped polycrystalline Si (poly‐Si) films were deposited as a function of the rf power (0–30 W) and deposition temperatureTd(600–750 °C) using disilane by a plasma‐enhanced chemical vapor deposition (PECVD) method. For comparison, poly‐Si films were also deposited using monosilane. The preferential orientation to a random, (100), or (110) texture was able to be selected by changing some of these deposition conditions. It was suggested that the change in the texture is caused by a change in the surface‐diffusion coefficient of SiHnadsorbates and by effects of an ion bombardment, rather than by a change in the deposition rate. For PECVD poly‐Si films, both the x‐ray relative intensity and the crystallinity rapidly decreased with decreasing the film thickness thinner than 0.4 &mgr;m. The value ofgin the electron spin resonance spectra and that of stress strongly depended on the rf power and the thickness. Further, when a film was annealed in H2plasma, the value ofgshifted from 2.0054 to 2.0043. These results are examined in terms of formation of different types of grain boundary which can be associated with a lattice deformation around the dangling bonds. ©1995 American Institute of Physics.