Development of Temperature Measurement Method in Micro-Scale Region by using Atomic Force Microscope.

随着科学技术的突飞猛进，在微观尺度上弄清换热特性成为一个非常重要的问题。本研究的目的是开发一种新的利用原子力显微镜(AFM)进行微尺度热测量的技术，该技术超越了普通的小尺寸温度测量技术。制备了探针和导电探针作为原子力显微镜的悬臂梁，T.C.探针由25微米的锐化镍丝和30纳米的金沉积膜组成，探针尖端的结长约为5微米。该电探头与热电探针具有相同的结构，由金丝和金膜制成，通过与导电样品或加热的非导电样品进行点接触，明确了接触半径、变形模式和电子传输模式等接触条件。点接触条件的电学和热学测量表明，接触半径分别约为10纳米和几纳米。这些小的接触尺度有可能完成高空间分辨率的热测量。在760Torr和0.02Torr的气氛中，通过对微小受热样品的扫描，获得了30微米和几个微米分辨率的温度分布。由于通过接触点的换热比通过头发的换热小得多，所以低压力条件下的热信号很小。为了实现更高分辨率的测量，减小TC结点尺寸是非常重要的。将热测量技术应用于碳纤维增强塑料(CFRP)环氧树脂/碳纤维复合材料样品的物理性能测试。通过选择合适的样品厚度，在真空条件下用亚微米尺度测量了不同材料的电导率和热导率的明显对比。

With a remarkable progress in science and technology, to make clear heat transfer characteristics in a microscopic scale is becoming great important issue. The purpose of this study is to develop a new technique for a micro-scale thermal measurement with AFM (Atomic Force Microscope) Which exceeds ordinary small scale temperature measurement techniques.In the project, special thermocouple (T.C.) probes and electric conductive probes were made as a cantilever for AFM.The T.C.probe composed of 25 micrometer sharpen nickel wire and 30 nano-meter gold deposition film has a junction of about 5 micrometer at a tip of the probe. The electric probe has same structure as the T.C.probe and made of gold wire and gold film.By making point contact between the probes and conductive sample or heated nonconductive sample, the contact condition has been clarified, such as contact radius, deformation mode and electron transport mode. Electric and thermal measurement of the point contact condition indicates the contact radius of about 10 nano-meter and a few nano-meter, respectively. These small contact scale has possibility of accomplishing thermal measurement with high spatial resolution.By scanning the T.C.probe on tiny heated sample, temperature distribution with 30 micrometer and a few micrometer resolution were sttained in 760 Torr and 0.02 Torr atmosphere. Since heat transfer through the contacting point is much smaller than that throughair, low pressure condition leads small thermal signal. For measurement with higher resolution it is important to reduce the T.C.junction size.The thermal measurement technique was applied to measure physical properties of a composite material sample of a Carbon Fiber Reinforced Plastic (CFRP) composed of epoxy resin and carbon fiber. By selecting suitable thickness of the sample, clear contrast of both electrical and thermal conductivity of the different materials was measured with sub-micron scale under vacuum condition.