Matsui Genzou, Kato Hideyuki
Hudson Laboratory, Bethel Co., Ltd., 4-6-12 Suginami, Ishioka, Ibaraki 315-0027, Japan.
Rev Sci Instrum. 2011 Mar;82(3):034905. doi: 10.1063/1.3557389.
Thermal diffusivity of Ti thin film with several hundred nanometers thickness has been measured by means of thermoreflectance (TR) technique and periodic heating using front heating and front detection configuration. Ti thin films were prepared on Si substrates by dc sputtering method. Then thin Mo layers as reflection layers were coated on Ti thin films. Surface of the Mo layer is irradiated by sinusoidally intensity modulated heating laser. Temperature response at the heated area is measured by a probe laser beam with constant intensity, as a TR signal. Phase lag between the phase of TR signal and that of heating laser beam was obtained from 100 kHz to 2.6 MHz. To analyze thermal diffusivity of Ti thin films using the phase lag data, we developed a three-layer analytical model such as Mo coating (100 nm)∕thin film∕semi-infinite substrate. The calculated phase lag using analytical model is in good agreement with the experimental data for the whole frequency range. The thermal diffusivity of two Ti thin films is determined to be 5 × 10(-6) m(2)∕s, which is 53% of the bulk one.
采用热反射（TR）技术并利用前加热和前检测配置进行周期性加热，测量了厚度为几百纳米的钛薄膜的热扩散率。通过直流溅射法在硅衬底上制备钛薄膜。然后在钛薄膜上涂覆薄钼层作为反射层。用强度正弦调制的加热激光照射钼层表面。用强度恒定的探测激光束测量加热区域的温度响应，作为TR信号。获得了TR信号相位与加热激光束相位之间在100kHz至2.6MHz范围内的相位滞后。为了利用相位滞后数据分析钛薄膜的热扩散率，我们建立了一个三层分析模型，如钼涂层（100nm）/薄膜/半无限大衬底。使用分析模型计算得到的相位滞后在整个频率范围内与实验数据吻合良好。确定两种钛薄膜的热扩散率为5×10（-6）m（2）/s，为块状钛热扩散率的53%。
