STRUCTURE AND GAS-SENSING CHARACTERISTICS OF UNDOPED TIN OXIDE THIN-FILMS FABRICATED BY ION-ASSISTED DEPOSITION

Undoped SnOx thin films were deposited by a reactive ion assisted depo sition technique at various ion beam potential (V-1) onto amorphous Si O2/Si substrates at room temperature. Crystalline structures of the fi lms were investigated in terms of grain size, composition ratio, poros ity and peak area percent of adsorbed oxygen. Sensitivities for propan e (C3H8), methane (CH4) and hydrogen (H-2) gas in SnOx gas sensor devi ces were characterized at the substrate temperatures of 100-500 degree s C. The gas sensitivities depend on the grain size rather than the po rosity. It is also proportioned to the amounts of adsorbed oxygen at r oom temperature by SPS analysis. (C) 1998 Elsevier Science S.A. All ri ghts reserved.