Abstract:  Ba 1－x Sr x TiO 3 （BST） thin films were firstly deposited on dry-oxidized silicon substrate by using the argon-ion beam sputtering technique and the silicon planner process．Next‚an annealing was carried out in oxygen atmo-sphere under different conditions．By means of the aluminum etching technique and the photoetching technique‚an a-luminum electrode was then made‚thus constructing the double dielectric capacitor structure of meta- l insulation-oxide-silicon （MIOS）．The charge storage character of the thin-film capacitor was finally investigated by the charge and dis-charge experiment．The results show that‚with the annealing temperature of no more than800℃‚the charge storageability of the thin film depends mainly on the oxygen ingredient．The more oxygen vacancies are‚the greater the charge storage ability is．

Key words:  Ba_1-xSr_xTiO₃ thin film, charge storage ability, MIOS structure, annealing, oxygen vacancy, trap