BaxSr1-xTiO3前驱多层膜制备及后热处理条件的优化

用Ar^~+离子束多靶溅射沉积技术在单晶硅Si(100)上顺序沉积了TiO₂、BaCO₃、SrCO₃叠层,并经后期低温扩散和高温晶化两步热处理过程制备了Ba_xSr_1-xTiO₃薄膜。用俄歇扫描电子能谱(AES)对其低温扩散效应(温度、时效、沉积顺序)进行了研究。实验结果表明:在低温段长时间保温或在中温段短时间保温都有利于各沉积组元充分扩散,扩散均匀的混合膜层经高温晶化(900℃)能形成多晶Ba_xSr_1-xTiO₃薄膜。

Multilayer Thin-film Synthesis of BaxSr1-xTiO3 Precursor and Post-annealing Processes for Final Phases

Multilayer thin-films Ba_xSr_1-xTiO₃ precursors (TiO₂, BaCO₃, SrCO₃) were deposited on Si (100) substrate by Ar⁺ ion beam sputtering layer by layer sequentially. The as-deposited films were post-annealed via two steps: diffusion at lower temperature and crystallization at higher temperature, in order to convert the multiplayer precursors into final phase of Ba_xSr_1-xTiO₃. Auger Electronic Spectrum (AES) concentration depth profiles were used to study the films’ diffusion through sequential precursor layers heat-treated at different temperatures, for varied holding time, and in the changed order of layer deposition. The results showed that both a long period of low-temperature and a short term of middle-temperature annealing were useful for the proper diffusion of the multiplayer precursors, and uniformly distributed compositions. The resultant Ba_xSr_1-xTiO₃ conld be crystallized at 900℃ from the fully annealed precursors.