A comprehensive study on the leakage current mechanisms of Pt/SrTiO₃/Pt capacitor

The leakage current characteristics of SrTiO₃ MIM capacitors, fabricated using atomic layer deposition, are investigated. The characteristics are highly sensitive to the polarity and magnitude of applied voltage bias, punctuated by sharp increases at high field. The characteristics are also asymmetric with bias and the negative to positive current crossover point always occurs at a negative voltage bias. In this work, a model comprising thermionic field emission and tunneling phenomena is proposed to explain the dependence of leakage current upon the device parameters quantitatively.