Thin‐film transistors were fabricated from polycrystalline silicon films which were produced by glow discharge decomposition of silane at 500 °C on thermal oxidized silicon substrates. The dependence of the crystalline and electrical properties was observed for thicknesses from about 500 to 4500 A˚. As the film grew thicker, the strongly (110) oriented polycrystalline structures became predominant. The conductivity changed from 4×10−9to 10−6(&OHgr; cm)−1and the activation energy from 0.57 to 0.5 eV. The field‐effect mobility of these thin‐film transistors also varied with the thickness of the film.