Solution-processed gate insulator was fabricated using polymethylphenylsilane (PMPS) as a liquid precursor. The spin-coated PMPS films were transformed into SiO(2) films after exposing to ultraviolet (UV) with 365 nm of wavelength. Fourier transform infrared spectra showed the variations of photo oxidation according to UV exposing time. The peak intensity of Si-O-Si bond increases with the UV energy, while the intensities of the methyl and phenyl peaks decrease. The electrical characteristics of PMPS-based spin-on glass (PMPS-SOG) were analyzed by capacitance-voltage and leakage current measurements. The dielectric constant was 4.14 and leakage current density was 10(-7) A/cm(2). The low temperature below 200 degrees C fabrication processing of PMPS-SOG could be achieved by UV exposing. PMPS-SOG, forming SiO(2), is applicable to gate insulator by low temperature solution-based process. (C) 2009 Elsevier B.V. All rights reserved.