Study on nano-scale thermophysical properties measurement method with Scanning Thermal Microscope

本研究旨在发展一种在扫描热显微镜上具有纳米尺度空间分辨率的局部热导率测量方法。制作了多功能微悬臂梁探针，并对其性能进行了实验研究。该悬臂梁为2微米厚、600微米长的SiO2基体，其上有5个热器件，探针末端有接触热电偶电极，用于检测接触温度，铂薄膜加热器用于校准热流传感器，热电堆传感器用于检测沿着悬臂梁的热流，薄膜热电偶用于测量悬臂梁体温度，另一个加热器用于控制硅基板附近的体温度。在高精度的局部导热系数测量中，要求同时测量接触热导和接触温度。研制的悬臂梁探针可用于热天平的标定 ...更多信息 le热流传感器与已知的铂加热器的加热，并识别热电薄膜热电偶的热电动力通过使用加热器的温度依赖性。通过消除微加工传感器的常见模糊性和引入自校准功能，提高了精度。将悬臂梁探针安装在基于AFM的SThM上，在低于10^ Pa的真空条件下工作，得到了如下结果<-4>：主动测温，其中热反馈补偿悬臂梁和样品之间的温差，可以提供比以前的测温探头更高的灵敏度。通过不断加热尖端附近的Pt加热器并利用热电堆传感器监测从探针到样品的热流，也可以获得具有高空间分辨率的热导成像。此外，通过将探针与涂覆有金薄膜的样品接触，在尖端处用接触式热电偶测量接触温度。这表明，同时测量的热导率和接触温度是可能的，并允许定量的局部热导率测量与SThM。少

This research aims to develop the local thermal conductivity measurement method with nano-scale spatial resolution on the scanning thermal microscope. With fabricating the multi-functional micro cantilever probe, its performance has been experimentally examined. The cantilever has 2 micron thick and 600 micron long body of SiO2, and five thermal devices on it. There is electrode of contact thermocouple at the end of the probe for detecting the contact temperature, Pt thin film heater for calibrating heat flow sensor next, thermopile sensor for detecting heat flow along the cantilever, thin film thermocouple for measuring cantilever body temperature and another heater for controlling the body temperature near Si base plate. For the local thermal conductivity measurement with high-accuracy, it is required to measure the contact thermal conductance and the contact temperature simultaneously with high accuracy. The cantilever probe developed in the research enable to calibrate the thermopi … More le heat flow sensor with known heating of the Pt heater, and to identifying thermoelectricmotive force of the thin film thermocouple by using temperature dependency of the heaters. Improvement in accuracy was conducted by eliminating the common ambiguity of the micro-fabricated sensors and introducing the self-calibration functions. It can lead the improvement in thermal conductivity measurement.Following results were obtained by attaching the cantilever probe on the SThM based on the AFM and operating under vacuum condition of below 10^<-4> Pa. The active thermometry, where thermal feedback compensates temperature difference between the cantilever and sample, can be available with higher sensitivity than a previous thermometry probe. Thermal conductance imaging with high spatial resolution can be also available by constantly heating the Pt heater near the tip and monitoring the heat flow from the probe to the sample with the thermopile sensor. Furthermore, the contact temperature is measured with the contact thermocouple at the tip by contacting the probe with the sample coated with gold thin film. It shows that the simultaneous measurement of the thermal conductance and the contact temperature is possible and allows the quantitative local thermal conductivity measurement with the SThM. Less