采用射频溅射制备BST薄膜,研究了薄膜的介电击穿特性.实验表明,在电压增大到传统击穿电压(电流密度出现瞬时增大时的电压)之前,薄膜性能已被破坏,发现在传统击穿状态之前存在另一个新状态———初始击穿状态.通过测试各状态的J-V(电流密度-电压)、J-T(电流密度-温度)特性分析其导电机理,建立了薄膜结构、漏电性能随电场强度增大而变化的模型.最后提出了确定实际意义上击穿电压的方法. The BST thin films were prepared by radio frequency sputtering and the dielectric breakdown characteristics of the films were investigated.The experimental results show that the properties of the films have been destroyed before the voltage increases to the traditional breakdown voltage (the instantaneous increase of the current density) Before the traditional breakdown state, there was another new state --- the initial breakdown state.After testing the JV (current density - voltage) and JT (current density - temperature) characteristics of each state, the conduction mechanism was analyzed and a thin film structure was established. The leakage performance changes with the increase of electric field strength.At last, the method to determine the breakdown voltage in practical sense is put forward.