RuO_2/Pt复合电极对BST梯度薄膜介电性能的影响

The effect of bottom hyrid electrode on the electric properties of the BST thin-films by magnetron sputtering

采用直流磁控溅射方法在Ti/SiO2/Si(100)衬底上制备RuO2/Pt复合电极,研究在复合电极上沉积的BST薄膜的微观结构及其对BST梯度薄膜电学性能的影响.实验结果表明:沉积在RuO2/Pt复合电极上的BST梯度薄膜在测试频率为100 kHz时,介电常数为324.8,介电损耗为0.0189;在75 kV/cm外电场下漏电流密度为1.29×10-6A/cm2;在Pt电极和RuO2/Pt复合电极上分别制备的BST薄膜的介电损耗和漏电流基本上相似,没有太大的区别.但在375 kV/cm外电场下RuO2/Pt复合电极上沉积的BST的介电调谐率为31.2%,比直接沉积在Pt上的BST的介电调谐率高7.4%,显示出较好的C-V特性.

The RuO2/Pt hybrid electrods were deposited on Ti/ SiO2/ Si（100） substrate by direct current sputtering technology. The effect of hybrid electrods On the microstructure and dielectric properties of the BST thin-films was investigated. The crystal phase structure and surface morphologies of the BST nano-films were characterized by XRD and AFM. The dielectric properties were measured using impedance analyzer. The results show that the dielectric constant is 324.8 and dielectric loss is 0. 018 9 for down-graded BST films deposited on RuO2/Pt hybrid electrods. The leakage current density of the films is 1. 29 ×10^-6 A/cm^2 at an electric field of 75 kV/cm. The dielectric tunability of the films deposited on RuO2/Pt hybrid electrods reaches 31. 2%, which is higher than the performance of the preparation of the BST thin film deposited on the Pt/Ti/SiO2/Si substrate directly. The results indicate that it is feasible to use the graded BST thin films as the requirements Microwave tunable devices.