Enhanced dielectric properties of highly (100)-oriented Ba(Zr,Ti)O₃ thin films grown on La[sub 0.7]Sr[sub 0.3]MnO₃ bottom layer

Abstract

Barium zirconate titanate Ba(Zr[sub 0.2]Ti[sub 0.8]O₃ (BZT) thin films on La[sub 0.7]Sr[sub 0.3]MnO₃ (LSMO)-coated Si and Pt/Ti/SiO₂/Si substrates have been prepared by pulsed laser deposition and crystallized in situ at 650 °C. Four capacitor types of LSMO/BZT/LSMO/Si, Pt/BZT/LSMO/Si, Pt/BZT/Pt/Si, and Pt/BZT/LSMO/Pt/Si were prepared to investigate the structural and dielectric properties, tunability, and figure of merits. Among them, the high (100)-oriented BZT films were grown on the (100)-textured LSMO and (111)-textured Pt electrodes. The results show that the LSMO/BZT/LSMO/Si has the highest dielectric constant of 555 and Pt/BZT/LSMO/Pt/Si has the highest tunability of 73% at 1 MHz. The high dielectric constant and tunability have been attributed to the (100) texture of the LSMO bottom layer leading to the decrease of the thickness of the interface of the dead layer.