Temperature measurement on submicron-area of thin films by using electron beam

利用具有良好空间分辨率的透射电子显微镜测量了薄膜的亚微米局域温度和导热系数。这种测量是基于样品中的热扩散散射效应，以及如果插入小孔，电子束透射率随温度的变化。这种高的空间分辨率是光测量无法达到的。1990年，我们尝试测量大规模集成电路中铝线上的局域温度，作为对多晶薄膜测量的扩展。AI线的晶粒度约为1微米，因此测量区域几乎由单晶组成。在单晶的情况下，由于布拉格衍射的变化和其他干扰，样品在加热时的轻微倾斜会降低准确度。然后，利用个人计算机自动测量多个点的传输，并且获得与这种干扰无关的传输。在300-550K温度范围内，测量精度约为&lt；正负50K。1991年，我们研究了用局部加热和激光相结合的方法测量薄膜的导热系数。激光输出采用正弦波调制，激光与局域温度之间的相位差由锁定放大器测量。这种方法具有不需要绝对温度测量和不需要知道薄膜物理常数的优点。对于厚度为200 nm的多晶铝薄膜，测量的电导率在30-100W/mK范围内变化。这是由于相位差到电导率的转换误差以及相位测量的误差造成的。激光辐照条件的精确确定需要对TIL的样品进行分析。我们对测量系统进行了改进，以准确地确定这一条件，并找到了误差较小的条件。

The local temperature on submicron-area and the thermal-conductivity of thin films are measured by using transmission electron microscopes (TEM) whose spatial resolution is excellent. This measurement is based on the thermal diffuse scatterino, effect in the specimen and on the change of electron beam transmission by the temperature if an aperture is inserted. This high spatial resolution can not be attained for the measurement with light.In 1990, we tried to measure the local temperature on Al lines in LSI as an expansion of measurement for polycrystalline films. The grain size of AI lines is about 1 mum, so the measuring area consists of almost single crystal. In the case of a single crystal, a slight tilt of the specimen by heating degrade the accuracy due to the change of Bragg diffraction and other interferences. Then, the transmission measured at many points automatically with a personal computer and the transmission independent of such interferences is obtained. The accuracy is about <plus-minus>50K in the range of 300-550 K at presenIn 1991, we investigated the measurement method of thermal conductivity of thin films by combining the local heating with a laser. The laser output is modulated by sine wave and the phase difference between the laser and the local temperature is measured by a lockin-amplifier. This method has some advantages that the absolute measurerdent of temperature does not need and it is no need to know the physical constant of films. For a polycrystalline Al film of 200nm in thickness, the measured conductivity varies in the range of 30-100 W/mK. This results from the error in the conversion form the phase difference to the conductivity as well as the error in the measurement of phase. The precise determination of laser irradiation condition needs for the specimen of TEIL. We improved the measurement system to determine this condition precisely and also found the condition in which the error is little.