摘要
在考虑探测光束光斑尺寸对调制光热反射(MPR)信号影响的基础上,建立了三维的薄膜-衬底体系的激光光热反射理论模型。对利用激光光热反射技术测量薄膜热物性的可行性进行了研究,并对影响调制光热反射信号的材料参数进行了分析。此外,通过数值模拟研究了多参数拟合问题,即利用调制光热反射频响信号同时确定薄膜热扩散率、衬底热扩散率和界面热阻这三个物理参数。结果表明,与已有的径向扫描方法相比,频率扫描方法中的这三个参数之间并不存在高度的相关性,因此采用频响信号进行多参数拟合,可提高多参数拟合的收敛性和精确性。
Considering the influence of the probe beam size on the modulated photothermal reflectance （MPR） signal, a three-dimensional theoretical model of laser-induced MPR for the thin film on-substrate system is presented in this paper. The feasibility of measuring the thermal parameters on thin films by MPR techniques is investigated. The effects of the material parameters on MPR signals are discussed in detail. The numerical multiparameter estimation of thermal properties is also performed in this paper using the frequency response of MPR signals （i. e. MPR frequency scanning method）. Three thermal parameters, i.e. the filmrs thermal diffusivity, the substrate＇s thermal diffusivity and the thermal resistance on the film-substrate boundary, are simultaneously determined. It is shown that, comparing with the conventional MPR radial scanning method, there is no strong correlation among the three thermal parameters in MPR frequency scanning model. Therefore the convergence and the accuracy of multiparameter estimation for samples can be improved by MPR frequency scanning method.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2006年第3期385-390,共6页
Chinese Journal of Lasers
基金
浙江省自然科学基金(Y104574)资助项目
关键词
激光技术
光热反射
多参数拟合
热扩散率
界面热阻
laser technique
photothermal reflectance
multiparameter estimation
thermal diffusivity
thermal boundary resistance
