Thin film transistors obtained by hot wire CVD

Hydrogenated microcrystalline silicon films obtained at low temperature (150-280 degrees C) by hot wire chemical vapour deposition at two different process pressures were measured by Raman spectroscopy, X-ray diffraction (XRD) spectroscopy and photothermal deflection spectroscopy (PDS). A crystalline fraction >90% with a subgap optical absortion 10 cm(-1) at 0.8 eV were obtained in films deposited at growth rates >0.8 nm/s. These films were incorporated in n-channel thin film transistors and their electrical properties Tn;ere measured. The saturation mobility was 0.72 +/- 0.05 cm(2)/ V s and the threshold voltage around 0.2 eV, The dependence of their conductance activation energies on gate voltages were related to the properties of the material. (C) 2000 Elsevier Science B.V. All rights reserved.