基于谐振法的高温环境下SiC微尺度杨氏模量测试

发布时间：2018-09-11 18:00

【摘要】：SiC材料是公认的高温半导体材料,在高温MEMS器件领域得到了越来越多的重视和应用。目前,针对其微尺度力学性能的研究已经取得了一定程度的进展,但仍未形成统一的力学参数标准,更是缺乏对高温环境下温度特性的研究。本文基于谐振法测量的原理,建立了基于组合悬臂梁的理论模型,搭建了适用于不同温度下的测试系统,获得了不同温度下微尺度SiC薄膜杨氏模量的力学参数,研究了其高温下的温度特性。具体包括以下几个方面的内容:1.基础理论研究:推导了微尺度薄膜材料杨氏模量的计算公式,分析了悬臂梁结构的设计准则,研究了膜厚对组合悬臂梁尺寸设计的影响,并通过仿真分析确定了悬臂梁结构的尺寸参数。2.测试系统搭建:关键在于高温环境的实现、高温环境下的激励及其检测。以MCH陶瓷加热片作为加热元件,K型热电偶作为温度传感元件,并利用红外测温仪测量实际温度,实现高温实验环境;采用机械激振器实现悬臂梁结构的激励;利用Polytec激光测振仪对振动频率进行检测。3.测试系统验证:对单晶硅[100]晶向的杨氏模量进行了测量。常温下的实验结果为132.5GPa,与文献值(129.5GPa)的误差为2.3%,验证了系统的可行性。对其不同温度下的杨氏模量值进行了测量。4.力学参数测试:对SiC薄膜杨氏模量的温度特性进行了研究。SiC样片的膜厚分别为5.3μm和7.9μm,常温下的实验结果分别为322.9±29.1GPa和345.5±40.8GPa。获得了微尺度SiC薄膜不同温度下的杨氏模量值,实验结果表明,随着测量温度的升高,杨氏模量呈现出明显的下降趋势。
[Abstract]:Silicon carbide (SiC) is a well-known high-temperature semiconductor material, which has attracted more and more attention and application in the field of high-temperature MEMS devices. At present, some progress has been made in the study of its micro-scale mechanical properties, but there is still no unified mechanical parameter standard, especially the study of temperature characteristics in high-temperature environment. Based on the principle of resonance method, a theoretical model of composite cantilever beam is established, and a testing system suitable for different temperatures is built. The mechanical parameters of Young's modulus of micro-scale SiC thin films at different temperatures are obtained, and the temperature characteristics at high temperatures are studied. The calculation formula of Young's modulus of micro-scale film material is given. The design criteria of cantilever beam structure are analyzed. The influence of film thickness on the dimension design of composite cantilever beam is studied. The dimension parameters of cantilever beam structure are determined by simulation analysis. 2. The test system is built: the key lies in the realization of high temperature environment, the excitation and detection of high temperature environment. MCH ceramic heating plate is used as heating element, K thermocouple is used as temperature sensing element, and infrared thermometer is used to measure the actual temperature to realize high temperature experimental environment; mechanical exciter is used to excite the cantilever beam structure; Polytec laser vibration detector is used to detect the vibration frequency. 3. Testing system verification: the crystal direction of single crystal silicon [100] The Young's modulus of SiC films was measured. The experimental results at room temperature were 132.5 GPa and the error was 2.3% compared with the reference values (129.5 GPa). The feasibility of the system was verified. The Young's modulus of SiC films at different temperatures was measured. 4. Mechanical parameters were tested: the temperature characteristics of Young's modulus of SiC films were studied. The thickness of SiC films was 5.3 microns, respectively. The Young's modulus of micro-scale SiC films at different temperatures was obtained. The results show that the Young's modulus decreases with the increase of temperature.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304.24;O348

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