六方钙钛矿介质薄膜的结构调制与微波介电特性研究

项目名称： 六方钙钛矿介质薄膜的结构调制与微波介电特性研究

项目编号： No.51302142

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 张效华

作者单位： 清华大学

项目金额： 25万元

中文摘要： 伴随微波集成线路的突飞猛进，微波介质薄膜化是器件发展的重要趋势。六方层状钙钛矿介质薄膜具有潜在应用价值。本申请拟通过晶体结构调制与元素取代，采用溶胶凝胶工艺和射频磁控溅射方法，在不同衬底上得到结构致密、均匀的六方层状钙钛矿AnBn-1O3n薄膜（A：Ba，La，Nd，B：Ti，Nb，Ta，Zr）。系统研究新型六方层状钙钛矿薄膜的晶体结构和微波介电特性。探讨薄膜的层状结构、晶体生长、应力状态与微波极化响应、频率温度系数之间的关联，实现高频介电特性的改善。通过离子占位，晶体结构和化学键揭示薄膜的微观极化响应机制，同时探讨薄膜的传导、电阻退化与弛豫机制，提供促使击穿和电阻退化的缺陷浓度，种类和激活能的物理信息，进而研究微波损耗机制。为六方层状钙钛矿薄膜的器件设计提供实验基础和理论依据。

中文关键词： 微波介质；MLCC；介电性能；温度系数；TSDC

英文摘要： With the recent progress of microwave interated circuits, the microwave dielectric films are the important trend of the device development.The hexagonal layered perovskite dielectric thin films are new microwave dielectric materials for the potential applications. This research is intended to rely on the crystal modulation and element replacement.And using sol-gel process and RF magnetron sputtering method,the dense and uniform hexagonal perovskite dielectric thin films AnBn-1O3n(A: Ba, La, Nd, B: Ti, Nb, Ta, Zr) are prepared on the different substrates. The crystal structures and microwave dielectric properties of the new hexagonal layered perovskite thin films will be systematically investigated. The relationship among the layered structure, crystal growth, stress state, microwave polarization response and the frequency temperature coefficient of hexagonal perovskite dielectric thin films will be discussed, which can achieve the improvement of the high-frequency dielectric properties. The microscopic polarization response mechanisms of dielectric thin films are revealed through the ionic occupancy, layered structure and chemical bond. Meanwhile, to obtain the microwave loss mechanisms,the conduction and resistivity degradaion and relaxation of dielectric thin films will also be investigated. The physical infor

英文关键词： Microwave dielectrics；MLCC；Dielectric properties；Temperature coefficient；TSDC