Phase and microstructural evolution during the interaction between bismuth oxide films and ptlti/SiO₂/Si substrates

Abstract

The interactions between metalogranically derived bismuth oxide films and Pt/Ti/SiO₂/Si substrates have been investigated in this study. The diffusion of bismuth species to the substrate and that of titanium species to the film surface occur during the heating processes, and pluralistic Bi-Ti-O phases are formed. With an increase in the heating temperature, the diffusion of titanium species is enhanced, thereby forming the compounds with a high Ti/Bi ratio in films. Based on analysis of SEM and AFM, the microstructure of films are significantly varied by the diffusion of titanium species, which results in the formation of large grains on film surface and causes a significant increase in roughness of films. The above results imply that the interface between bismuth-layered perovskite films and Pt/Ti/SiO₂/Si substrates would be influenced by the interdiffusion of bismuth and titanium species.

Key Words:

• bismuth oxide
• titanium
• film; diffusion
• microstructure