混合失配模型预测金属/半导体界面热导

Mixed mismatch model predicted interfacial thermal conductance of metal/semiconductor interface

声学失配模型和漫散射失配模型被广泛应用于界面热导的计算,两种模型分别建立在极端光滑和粗糙界面的假设基础上.由于实际界面结构与两种假设的区别较大,造成两种模型预测结果与实际界面热导偏差较大.近期提出的混合失配模型考虑了界面结构对声子镜面透射和漫散射透射比例的影响,预测的准确度有所提高.但该模型需要通过分子动力学模拟获取界面声子信息较为复杂.为此,本文通过引入测量的粗糙度数值简化混合失配模型,并增加考虑界面结构对接触面积的影响,实现对界面热导简单快捷、准确地预测.基于该模型,计算预测了金属(铝、铜、金)和半导体(硅、碳化硅、砷化镓、氮化镓)的界面热导.并将铝/硅界面的结果与实验测量结果对比,数据吻合较好.该模型不仅有助于界面导热机理的理解,而且利于与测量结果对比.

The acoustic mismatch model and diffuse mismatch model are widely used to calculate interfacial thermal conductance.These two models are respectively based on the assumption of extremely smooth and rough interfaces.Owing to the great difference between the actual interface structure and the two hypotheses,the predictions of these two models deviate greatly from the actual interfacial thermal conductance.The recently proposed mixed mismatch model considers the effect of interface structure on the ratio of phonon specular transmission to diffuse scattering transmission,and the prediction accuracy is improved.However,this model requires molecular dynamics simulation to obtain phonon information at the interface.In this work,the mixed mismatch model is simplified by introducing the measured roughness value,and the influence of interface structure on the contact area is taken into account to achieve a simple,fast and accurate prediction of interface thermal conductance.Based on this model,the interfacial thermal conductances of metals(aluminum,copper,gold) and semiconductors(silicon,silicon carbide,gallium arsenide,gallium nitride) are calculated and predicted.The results of Al/Si interface are in good agreement with the experimental results.This model is helpful not only in understanding the mechanism of interface heat conduction,but also in comparing with the measurement results.