Thermal Transport Mechanism of Amorphous HfO_(2):A Molecular Dynamics Based Study  

作　　者：ZHANG Honggang WEI Han BAO Hua 

机构地区：[1]University of Michigan-Shanghai Jiao Tong University Joint Institute,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Journal of Thermal Science》2022年第4期1052-1060,共9页热科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)(No.12104291)and(No.51676121)。

摘　　要：Amorphous hafnium dioxide(a-HfO_(2))has attracted increasing interest in the application of semiconductor devices due to its high dielectric constant.However,the thermal transport properties of a-HfO_(2) are not well understood,which hinders its potential application in electronics.In this work,we systematically investigate the thermal transport property of a-HfO_(2) using the molecular dynamics method.The non-equilibrium molecular dynamics simulations reveal that the thermal conductivity of a-HfO;is length-dependent below 100 nm.Spectrally decomposed heat current further proves that the thermal transport of propagons and diffusons is sensitive to the system length.The thermal conductivity is found to increase with temperature using Green-Kubo mode analysis.We also quantify the contribution of each carrier to the thermal conductivity at different temperatures.We find that propagons are more important than diffusons in thermal transport at low temperatures(<100 K).In comparison,diffusons dominate heat transport at high temperatures.Locons have negligible contribution to the total thermal conductivity.

关 键 词：amorphous HfO2 molecular dynamics thermal conductivity mean free path size effect temperature effect 

分 类 号：TK124[动力工程及工程热物理—工程热物理]