AlN/金刚石新型层状复合结构上SAW高温敏感特性研究

项目名称： AlN/金刚石新型层状复合结构上SAW高温敏感特性研究

项目编号： No.11474203

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 韩韬

作者单位： 上海交通大学

项目金额： 105万元

中文摘要： 高声速、固有损耗低的氮化铝(AlN)压电薄膜具有作为耐高温声表面波传感器敏感材料的潜力。国际上这方面的研究刚刚起步，亟待在层状复合界面结构器件的精确建模、高质量择优取向AlN薄膜的高温性能劣化机制以及宽温度范围内传感器温度补偿等基础理论和关键技术方面取得进一步突破。 本研究拟采用相对于参考状态的Lagrangian坐标系，推导出包含电扰动项并适用于存在多场耦合的压电介质的非线性电弹扰动方程。采用有限元结合微扰理论求解SAW传感器的应力应变分布以及谐振频率、插损、阻抗等力学和电学输出，用于多层复合结构传感器的模态选择和参数优化。提出并制备一种具有无源温度补偿功能的新型AlN(IDT)/金刚石/AlN多层复合结构，实现在900℃稳定工作时间超过500小时的高温敏感材料，并在800℃±100℃范围内进行温度补偿，双SAW谐振器差分输出的频偏小于60ppm.

中文关键词： 声表面波；氮化铝薄膜；高温传感器

英文摘要： Aluminum nitride(AlN) has been identified as an interesting piezoelectric material candidate for SAW sensors at high temperature.However,the experimental research has just started in few countries.The breakthrough of the accuracy modeling of the layered composite SAW devices, the mechanism of the performance deterioration of AlN film under high temperature, and the temperature compensation technique within a wide temperature range are expected in the coming research. In this proposal,the nonlinear thermoelectroelastic equation for layered composite superposed on multiphysical biasing fields will be setup.Both the mechanical parameters, such as the stress as well as the strain distribution and the electrical parameters of the SAW devices should be simulated using the model.The surface wave modes within the layered composite and the topology of the sensor can be optiminized. A novel structure with four layers- - AlN/diamond/AlN with buried IDT within AlN film is proposed. The fabricated composite with optimized thickness of each layer is expected to be operated long-term at about 900 C in the time scale of 500 hours, and it can be passively compensated at 800℃ with extremely small frequency variation of 60ppm in wide temperature range between 700℃ and 900℃.

英文关键词： surface acoustic wave;AlN thin fim;high temperature sensors