RF MAGNETRON SPUTTERING CONDITION DEPENDENCES OF DIELECTRIC NON-LINEARITY OF Ba_0.6Sr_0.4TiO₃ THIN FILMS

ABSTRACT

Barium strontium titanate (Ba_0.6Sr_0.4TiO₃, short for BST) thin films were prepared by RF-magnetron sputtering. The influences of deposition conditions, such as sputtering power, deposition pressure and sputtering gas, on the microstructures and dielectric non-linearity of BST thin films were investigated. The results show that both dielectric constant and tunability of BST films increase and then decrease as the sputtering power increases. Moreover, the tunability increases as O₂:Ar ratio increases from 1:1 to 8:1. Not only the ratios of (Ba+Sr)/Ti and Ba/Sr but also the RMS roughness increases with increasing deposition pressure.

Keywords::

• Barium strontium titanate
• thin film
• dielectric non-linearity
• sputtering condition