氮化镓/金刚石异质结构界面热输运特性的分子动力学研究  

Molecular Dynamics Study on Thermal Transport Characteristics of GaN/Diamond Heterostructure Interface

作　　者：陆吕杰 魏宁 Lu Lüjie;Wei Ning(School of Mechanical Engineering,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学机械工程学院,江苏无锡214122

出　　处：《微纳电子技术》2024年第10期66-72,共7页Micronanoelectronic Technology

摘　　要：金刚石具有极高的热导率,作为衬底材料在解决氮化镓基电子器件的散热问题上前景良好。穿过界面的声子传输行为决定了氮化镓/金刚石异质结构界面的热性能。采用非平衡分子动力学方法研究了尺寸、温度以及空位缺陷对氮化镓/金刚石界面热导率的影响,通过声子态密度及其重叠因子对界面热导率的变化进行微观分析。研究表明,在热输运方向上异质结构长度尺寸变化时,界面热导率无明显变化且始终在0.39~0.42GW/(m^(2)·K)。当提高外界温度时,界面热导率也随之增大,并且在400K下达到0.46GW/(m^(2)·K)。温度升高导致晶格振动剧烈,界面处的声子匹配度增加。引入空位缺陷后,由于空位缺陷会导致声子频率降低并且增加声子的散射,界面热导率在30%的空位缺陷浓度下为0.24GW/(m^(2)·K)。该研究结果有助于调控氮化镓基半导体器件的热输运性能,并为异质界面器件的设计提供理论了参考。Diamond has a very high thermal conductivity,and as a substrate material,it has a good prospect in solving the heat dissipation problem of GaN-based electronic devices.The phonon transport behavior across the interface determines the thermal performance of the GaN/diamond heterostructure interface.The influences of size,temperature and vacancy defects on the thermal conductivity of the GaN/diamond interface were investigated using non-equilibrium molecular dynamics method.The change of interface thermal conductivity was analyzed microscopically through the phonon density of states and their overlap factors.The study shows that when the heterostructure length changes in the direction of thermal transport,the interface thermal conductivity does not change significantly and is always 0.39-0.42 GW/(m^(2)·K).When the external temperature is increased,the interface thermal conductivity also increases,and the interface thermal conductivity reaches 0.46 GW/(m^(2)·K)at 400 K.The increase of temperature causes more intense lattice vibration,thus the phonon matching degree at the interface increases.After introducing of the vacancy defect,the interface thermal conductivity is 0.24 GW/(m^(2)·K)at 30%vacancy defect concentration,because the vacancy defects will cause the phonon frequency to decrease and the phonon scattering to increase.The research results are helpful to regulate the thermal transport properties of GaN-based semiconductor devices,and provide a theoretical reference for the design of heterostructure devices.

关 键 词：界面热导率 尺寸效应 温度效应 空位缺陷 分子动力学 

分 类 号：TN41[电子电信—微电子学与固体电子学] TB34[一般工业技术—材料科学与工程]