Dielectric and interface characteristics of SrTiO₃ with a MIS structure

SrTiO₃(STO) films were deposited onto the p-type Si substrates by metal-organic decomposition (MOD) technique. The dielectric and interface characteristics of STO with a metal-insulator-semiconductor (MIS) structure were investigated. The results showed that the dielectric constant was about 105 and the dissipation factor was lower than 0.01 for our STO films at a frequency of 10 kHz. The excellent dielectric properties were attributed to the polycrystalline structure with good crystallinity. The fixed charge density N_f and the interface-trap density D_it were calculated to be about 1.5×10¹²cm^-2 and (1.4-3.5)×10¹²cm^-2 eV^-1, respectively. Both N_f and D_it were mainly connected with an interface layer with low dielectric constant formed at the interface of Si/STO.