薄膜微量热计的信号采集与处理模块设计

Design on signal acquisition and processing module for a thin-film microcalorimeter

薄膜微量热计是测量亚微米厚度薄膜热动力学特性的重要手段,针对薄膜微量热计的脉冲扫描量热测试方法改进了系统的信号采集与分析模块。微量热计原始信号经高精度仪用放大电路后,由高速数据采集卡采集送入PC机;采用LabVIEW软件编写的控制程序并采用Matlab软件实现数据的分析处理。对加载了70 nm厚度In薄膜的微量热计进行热容测试,观测到了In薄膜的熔化峰和熔点,表明系统具有足够高的信噪比和检测灵敏度。

Thin film microcalorimeter is an important technology for thermodynamic measurements of thin films with sub-micron thickness. The signal acquisition and analysis module for a pulse mirocalorimetry system are improved. With a high precision instrumentation amplifier and a high-speed data acquisition card, the original signal of the microcalorimeter is amplified and collected, and sent to PC. With LabVIEW and Matlab software, the control program and data analysis are designed. The microcalorimeter with 70 nm In thin-film is measured with this pulse mirocalorimetry system, and a peak is observed at the heat capacity curve and the melting point is obtained. It shows that the system has enough high signal to noise ratio and detecting sensitivity.