Thin-film solid electrolytes, lithium sulfur oxynitride (Lison), were fabricated by radio-frequency (rf) magnetron sputtering under various gas compositions. Composition of the thin film was determined by atomic absorption spectroscopy, Rutherford back-scattering spectroscopy, and energy-dispersive X-ray spectrometry. The ionic conductivity of the thin film at room temperature showed a maximum of 2 x 10(-5) S/cm for Li0.29S0.28O0.35N0.09. Microstructure of Lison thin films shows an amorphous nature when deposited under nitrogen atmosphere. The electrolyte was stable up to 5.5 V vs. Li/Li+. (C) 2004 The Electrochemical Society.