Modelling and experimental validation of thin-film effects in thermopile-based microscale calorimeters
Modelling and experimental validation of thin-film effects in thermopile-based microscale calorimeters
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DOI：
10.1016/j.sna.2008.11.037
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发表时间：
2009-03-25
影响因子：
4.6
通讯作者：
Charette, Paul G.
中科院分区：
文献类型：
--
作者：
Bourque-Viens, Alexandre;Aimez, Vincent;Charette, Paul G.
量热计可以小型化到可以集成到微全分析系统（mu TAS）或芯片实验室等平台中的程度。微尺度量热计的模型目前无法解释已知存在于薄膜中的材料性质的变化。本研究试图解决这一缺陷。金、镍薄膜的电阻率和绝对塞贝克系数在亚微米范围内随薄膜厚度的倒数呈线性变化。制作了由金和镍组成的薄膜热电堆，并测量了它们的电阻和灵敏度。我们的结果表明，薄膜效应可引起灵敏度（温度-电压转换比）降低15%，分辨率（最小可分辨温差）降低30%。将材料性质随膜厚度的变化引入热电堆性能模型中，导致了估计的改进。模拟结果表明，晶界散射是一个强大的贡献者所观察到的膜厚度相关的电阻率和塞贝克系数的变化。这些观察结果对改进基于热电堆和其他微加工的微尺度量热计的设计和制造具有影响。(C)2009爱思唯尔有限公司版权所有。
Calorimeters can be miniaturized to the point where they can be integrated into platforms such as micro-total analysis systems (mu TAS) or lab-on-chip. Models of microscale calorimeters currently fail to account for variations of material properties known to be present in thin films. This study attempts to address this deficiency. Resistivity and absolute Seebeck coefficient of gold and nickel thin films were found to vary linearly with the inverse of film thickness in the submicron range. Thin-film thermopiles composed of gold and nickel were fabricated and their resistance and sensitivity were measured. our results show that thin-film effects can introduce a 15% decrease in sensitivity (temperature-to-voltage conversion ratio) and a 30% decrease in resolution (smallest resolvable temperature difference). Introducing material properties variation with film thickness into models of thermopile performance resulted in improved estimates. Modelling results suggest that grain boundary scattering is a strong contributor to the observed film-thickness-related change of resistivity and Seebeck coefficient. These observations have implications for improving the design and fabrication of thermopile-based, and other microfabricated, microscale calorimeters. (C) 2009 Elsevier B.V. All rights reserved.