The effects of post excimer laser annealing on (Ba,Sr)TiO3 thin films at low substrate temperatures

Abstract

The amorphous (Ba,Sr)TiO3 (alpha-BST) films sputtered onto the Pt/TiN/Ti/Si substrates are greatly improved using the excimer laser annealing (ELA) technique of wavelength 248 nm at low substrate temperature 300degreesC. The dielectric constant of the alpha-BST film is remarkably enhanced from 80 to over 250 after ELA treatment. The heat conduction analysis indicates that a very shallow light absorption depth of the wavelength 248 nm for the BST film behaves an excellent thermal property, which doesn't,damage the underlayer films during ELA treatment. Besides, the leakage current of ELA-BST films is strongly influenced by the laser energy fluence (LEF). The detailed mechanisms of the crystallinity and the electric properties am systematically studied in this report.