Au/Si基片上沉积Bi_(1.5)Zn_(1.0)Nb_(1.5)O_7薄膜介电性能的研究

Study on Dielectric Properties of Thin Films on Au/Si Substrate

采用磁控溅射法在Au／Si基片上制备了铌酸锌铋BZN（Bi1.5Zn1.0Nb1.5O7）薄膜。在基片温度200℃、本底真空1×10^-3Pa条件下，BZN靶溅射0．5h，作为自缓冲层；然后在400℃下溅射1．5h，薄膜总厚度为200nm，650℃原位真空退火1h。XRD分析显示该薄膜为〈222〉单一取向，结晶良好；AFM扫描显示表面平整；测试表明不同频率下薄膜的性能没有大的改变。实验证明，选用电阻率较小的Au电极材料有利于器件性能的提高，实验得到介电常数可调率约20％、损耗为0．002-0．004。

BZN （Bi1.5Zn1.0Nb1.5O7） thin films with a buffer layer were deposited by facing magnetron sputtering from BZN onto Au/Si substrates at 200 ℃ and 1 × 10^3 Pa for 0.5 h. The thin film with 200 nm total thickness was prepared at 400 ℃ for 1.5 h and subsequent in situ annealing at 650 ℃ for 1 h. X-ray diffraction （XRD）shows that BZN thin film is 〈222〉 orientated with good crystallinity. The surface of BZN thin film was showed to be smooth by AFM. Testing result shows that the different frequencies have a slight deffect on the dielectric propertids. The experiments prove that the property of the device by Au electrode can be improved with lower resistivity. It can be obtained that the dielectric loss of the film is 0.002 - 0. 004 and the dielectric constant tunability is about 20%.