Influence of TiO2 adhesion layer thickness on properties of (Ba,Sr)TiO3 thin films

Abstract

(Ba0.5Sr0.5)TiO3 thin films were deposited on Pt/TiO2/SiO2/Si Substrates with various TiO2 adhesion layer thicknesses. The crystallinity of Pt thin films with (111) direction and the electrical properties of BST thin films strongly depend on the TiO2, adhesion layer thickness. TiO2 adhesion layers between the Pt and SiO2 layers with thicknesses smaller than 5 nm show good adhesion properties and a low leakage current density of BST thin films deposited on the Pt/TiO2/SiO2/Si substrate, which is lower than 8.8 x 10(-8) A/cm(2) at an applied voltage of 1 V. The optimal thickness of the TiO2 adhesion layer in the Pt/TiO2/ SiO2/Si structure is very important to obtain good electrical properties of BST thin films as well as good adhesion properties.