磁控溅射参数对钛酸锶钡薄膜生长及介电性能的影响

Influence of magnetron sputtering parameters on the growth of barium strontium titanate thin films and dielectric properties

使用射频磁控溅射系统在Pt/SiO_2/Si基片上沉积了Ba_(0.6)Sr_(0.4)TiO_3(BST)薄膜,研究了溅射过程中氧氩比与溅射总气压对BST薄膜生长过程及介电性能的影响。通过XRD衍射仪、原子力显微镜等对在不同条件下制备出的薄膜样品进行了性能测试和分析。结果表明:增加氧氩比能够增加薄膜表面晶粒尺寸,提升薄膜的结晶度,增加薄膜的介电常数并降低介电损耗,但同时也会降低薄膜的沉积速率;增加溅射气压会导致薄膜表面晶粒尺寸减小、结晶度降低,薄膜的沉积速率随着溅射气压的增加呈现先增加后降低(溅射气压大于2Pa时)的趋势。

The Ba_（0.6）Sr_（0.4）TiO_3（BST）thin films were deposited on Pt/SiO_2/Si substrates by an radio frequency magnetron sputtering.The influence of the ratio of O2 and Ar and pressure on the growth process and dielectric properties of BST thin films are investigated.The process of sputtering atmosphere on the BST film growth is studied with an atomic force microscope（AFM）and an X-ray diffractometer.The dielectric properties of BST films are measured by an Agilent impedance analyzer.The results show that the grain size,crystallinity and dielectric constant of thin films increase with the ratio of O_2 and Ar,which decreases the dielectric loss but diminishes the depositing speed at the same time.The increasing of sputtering pressure lead the decrease of the grain size and crystallinity of BST thin films.The growth rate of BST thin films increases first and then decreases with sputtering pressure.