摘要
为实现高质量多晶金刚石膜的可控制备,采用6 kW/2 450 MHz微波等离子体化学气相沉积(Microwave Plasma Chemical Vapor Deposition, MPCVD)系统,以单晶硅为衬底,通过成核工艺调控微米级多晶金刚石膜的外延生长.系统研究了成核阶段的衬底温度、腔体压强、甲烷流量及成核时间对微米级多晶金刚石膜外延生长的影响,获得了利于微米级多晶金刚石膜高质量外延生长的最优成核工艺.结果表明:在衬底温度750℃、压强12 kPa、甲烷流量36 mL/min、成核时间2.5 h的优化条件下,所获成核层初始晶粒尺寸为2~3.5μm,晶界缺陷密度显著降低,展现出良好的结晶基础.成核参数直接影响生长行为:适宜的衬底温度(750℃)有效平衡了碳迁移与氢刻蚀作用;优化的甲烷流量(36 mL/min)在保障碳源供给的同时抑制了非金刚石相沉积;适当的腔体压强(12 kPa)维持了均匀的等离子体能量分布;合理的成核时间(2.5 h)确保了晶粒充分合并与取向优化.基于该优化成核工艺制备了厚度为10.87μm的多晶金刚石膜:晶体取向以(111)面为主,平均晶粒尺寸为3.7μm,残余应力和本征应力分别低至-0.983 GPa和0.381 GPa,拉曼光谱中金刚石特征峰半高宽仅为4.33 cm-1,展现出优异的结晶质量.综合分析表明,优化的成核工艺有效促进了晶粒粗化、缺陷抑制及残余应力控制,为多晶金刚石膜的连续高质量生长提供了核心保障,显著提升了薄膜综合性能.本研究为高性能多晶金刚石热管理材料的可控制备提供了可复制的工艺方案与实验依据.
To achieve controllable preparation of high-quality polycrystalline diamond films,this study employed a 6 kW/2450 MHz microwave plasma chemical vapor deposition(MPCVD)system,with single-crystal silicon as the substrate,to regulate the epitaxial growth of micrometer-scale polycrystalline diamond films through nucleation process optimization.The effects of substrate temperature,chamber pressure,methane flow rate,and nucleation time on the epitaxial growth were systematically investigated,leading to the identification of an optimized nucleation process conducive to high-quality film growth.Results demonstrated that under the optimized conditions(substrate temperature:750℃;chamber pressure:12 kPa;methane flow rate:36 mL/min;nucleation time:2.5 h),the resulting nucleation layer exhibited an initial grain size of 2~3.5μm,a significantly reduced grain boundary defect density,and a sound foundation for crystallization.These nucleation parameters critically influence the growth behavior:a temperature of 750℃effectively balances carbon migration and hydrogen etching;a methane flow rate of 36 mL/min ensures adequate carbon supply while suppressing non-diamond phase formation;a pressure of 12 kPa maintains uniform plasma energy distribution;and a nucleation time of 2.5 h facilitates sufficient grain coalescence and orientation optimization.By employing this optimized nucleation process,a polycrystalline diamond film with a thickness of 10.87μm was deposited,which demonstrated a predominant(111)crystal orientation,an average grain size of 3.7μm,residual and intrinsic stresses as low as-0.983 GPa and 0.381 GPa,respectively,and a narrow diamond Raman peak with a full width at half maximum of only 4.33 cm-1:Collectively indicating exceptional crystalline quality.Comprehensive analysis revealed that the optimized nucleation process effectively promoted grain coarsening,defect suppression,and residual stress control,thereby providing a critical foundation for the continuous high-quality growth of polycrystalline diamond films and significantly enhancing their overall performance.This study provides a reproducible technical strategy and experimental basis for the controllable fabrication of high-performance polycrystalline diamond films intended for thermal management applications.
作者
朱领龙
郭胜惠
叶小磊
杨黎
赵俊贤
周子奇
ZHU Linglong;GUO Shenghui;YE Xiaolei;YANG Li;ZHAO Junxian;ZHOU Ziqi(State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,Kunming University of Science and Technology,Kunming 650093,China;Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China)
出处
《昆明理工大学学报(自然科学版)》
北大核心
2025年第6期13-25,共13页
Journal of Kunming University of Science and Technology(Natural Science)
基金
国家自然科学基金项目(52374389,52364051)
云南省彩云博后创新项目资助项目(CG24056E003A)
云南省重大科技专项(202502AB080008)。
关键词
微波等离子体化学气相沉积
多晶金刚石膜
缺陷密度
残余应力
microwave plasma chemical vapor deposition
polycrystalline diamond film
defect density
residual stress
