The zirconium doped (Ba0.65Sr0.35)(Ti1−xZrx)O3 thin films for gbit-scale dynamic random access memory device applications

Abstract

High dielectric constant (Ba0.65Sr0.35)(Ti1−xZrx)O3 (BSTZ) thin films with different Zr content were prepared on Pt/Ti/SiO2/Si substrates at 500°C by rf magnetron sputtering technique. The grain size, dielectric constant, and leakage current density of the 90 nm thick BSTZ films decreased with increasing Zr content. The dielectric constant and dissipation factor of BSTZ films with Zr content of 0.26 were 390 and 0.025 at an applied frequency of 100 kHz, respectively. The leakage current density of films was about 9.0 × 10−9 A/cm2 at 200 kV/cm. The decrease of leakage current density with increasing Zr content was due to increase of Schottky barrier height. The BSTZ films deposited by rf magnetron sputtering were attractive for semiconductor memory capacitor application.