Leakage current of Pt∕(Ba0.7Sr0.3)TiO3 interface with dead layer

Leakage current of $\mathrm{Pt}∕\left({\mathrm{Ba}}_{0.7}{\mathrm{Sr}}_{0.3}\right)\mathrm{Ti}{\mathrm{O}}_3$ (BST)∕$\mathrm{Y}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ capacitors on a (001) $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_3$ substrate was studied. By modeling a low-dielectric constant layer, a so-called dead layer, between the Pt∕BST interface as a parasitic capacitor in series with the bulk layer capacitor, the leakage current of Pt∕BST interface was well analyzed based on the modified Schottky emission equation. Furthermore, a two-step schematic energy band diagram is proposed to explain the carrier transport through the Pt∕BST interface.