基于分子动力学的氮化镓/石墨烯/金刚石界面热导研究  

Interfacial thermal conductance of gallium nitride/graphene/diamond heterostructure based on molecular dynamics simulation

作　　者：刘东静[1,2] 胡志亮 周福 王鹏博 王振东 李涛 Liu Dong-Jing;Hu Zhi-Liang;Zhou Fu;Wang Peng-Bo;Wang Zhen-Dong;Li Tao(Guangxi Key Laboratory of Manufacturing System&Advanced Manufacturing Technology,School of Mechanical andElectrical Engineering,Guilin University of Electronic Technology,Guilin 541004,China;Guilin Research and Creation Semiconductor Technology Limited Liability Company,Guilin 541004,China)

机构地区：[1]广西制造系统与先进制造技术重点实验室,桂林电子科技大学机电工程学院,桂林541004 [2]桂林研创半导体科技有限责任公司,桂林541004

出　　处：《物理学报》2024年第15期49-58,共10页Acta Physica Sinica

基　　金：广西制造系统与先进制造技术重点实验室主任基金(批准号:19-050-44-002Z);2024年度广西高校中青年教师科研基础能力提升项目(批准号:2024KY0203);桂林电子科技大学研究生教育创新计划(批准号:2024YCXS016);2023年广西自治区级新工科研究与实践项目(批准号:XGK202309)资助的课题

摘　　要：为解决氮化镓芯片散热问题,采用非平衡分子动力学法,研究工作温度、界面尺寸、缺陷率及缺陷类型对氮化镓/石墨烯/金刚石异质界面热导的影响,通过计算声子态密度和声子参与率,分析界面热传导机理.研究发现,在100—500 K范围内,温度升高使界面热导增大2.1倍,重叠因子随温度增加而增加,界面间声子耦合程度增强,界面热导相应增大.当氮化镓层数从10层增加到26层时,界面热导降低75%,分析认为是界面声子耦合程度下降导致.另外,添加5层石墨烯会导致界面热导降低74%,分析认为是声子局域化程度加重造成;当缺陷率从0增大到10%时,金刚石碳原子缺陷使界面热导提高40%,缺陷散射增加低频声子数量,改善界面热传导;但镓、氮和石墨烯碳原子缺陷会加重声子局域化程度,均导致界面热导降低.研究结果有助于提升氮化镓芯片散热性能,同时对高可靠性氮化镓器件设计具有指导意义。Gallium nitride chips are widely used in high-frequency and high-power devices.However,thermal management is a serious challenge for gallium nitride devices.To improve thermal dissipation of gallium nitridedevices,the nonequilibrium molecular dynamics method is employed to investigate the effects of operating temperature,interface size,defect density and defect types on the interfacial thermal conductance of gallium nitride/graphene/diamond heterostructure.Furthermore,the phonon state densities and phonon participation ratios under various conditions are calculated to analyze the interface thermal conduction mechanism.The results indicate that interfacial thermal conductance increases with temperatures rising,highlighting the inherent self-regulating heat dissipation capabilities of heterogeneous.The interfacial thermal conductance of monolayer graphene structures is increased by 2.1 times as the temperature increases from 100 to 500 K.This is attributed to the overlap factor increasing with temperature rising,which enhances the phonon coupling between interfaces,leading the interfacial thermal conductance to increase.Additionally,in the study it is found that increasing the number of layers of both gallium nitride and graphene leads the interfacial thermal conductance to decrease.When the number of gallium nitride layers increases from 10 to 26,the interfacial thermal conductance decreases by 75%.The overlap factor diminishing with the layer number increasing is ascribed to the decreased match of phonon vibrations between interfaces,resulting in lower thermal transfer efficiency.Similarly,when the number of graphene layers increases from 1 to 5,the interfacial thermal conductance decreases by 74%.The increase in graphene layers leads the lowfrequency phonons to decrease,consequently lowering the interfacial thermal conductance.Moreover,multilayer graphene enhances phonon localization,exacerbates the reduction in interfacial thermal conductance.It is found that introducing four types of vacancy defects can affect

关 键 词：界面热导 温度效应 尺寸效应 空位缺陷 

分 类 号：TN405[电子电信—微电子学与固体电子学] TK124[动力工程及工程热物理—工程热物理]