摘要
异质外延为金刚石晶圆合成提供了一个有效的实现路径,而Ir衬底上金刚石形核生长技术经过20多年的发展已经有能力制备最大直径为3.5英寸的晶体,开启了金刚石作为终极半导体在电子信息产业应用的大门。然而,表面形核、偏压技术窗口、金刚石外延生长等一系列发生在异质衬底上的问题都需要从生长热力学的角度给予解释。本研究针对化学气相沉积气氛中金刚石如何实现外延形核与生长这一关键问题,利用第一性原理计算从原子尺度对金刚石形核生长过程展开了系列探究。研究结果如下:C原子在Ir衬底表面位点吸附比在体相位点吸附更稳定,表明无偏压条件下金刚石形核只能在衬底表面发生;离子轰击作用下非晶氢化碳层中sp3杂化C原子个数随着离子动能的增加呈现先增大后减小的变化规律,证实了金刚石高密度形核存在一定的离子动能与偏压大小窗口;金刚石沿着Ir衬底外延生长时界面结合能最低(约为–0.58 eV/C),意味着界面结合能是决定外延形核生长的主要热力学因素。本研究阐明了偏压辅助离子轰击促进金刚石单晶外延生长的热力学机制,对于指导金刚石及其他碳基半导体生长具有重要意义。
Heteroepitaxy provides an effective path for the synthesis of diamond wafers.After more than 20 years of development,the diamond nucleation and growth technology on iridium substrates has enabled to prepare crystals with a maximum diameter of 3.5 inches,which opens a door to application diamond as ultimate semiconductor in the future chip industry.However,a series of problems that occur on heterogeneous substrates,such as surface nucleation,bias process window,and diamond epitaxial growth,need to overcome from the perspective of growth thermodynamics.In this study,aiming at the key issue how diamond can achieve epitaxial nucleation and growth in chemical vapor deposition atmosphere,a simulation study was carried out on the nucleation and growth process of diamond at the atomic scale based on the first-principle calculation.The results show that the adsorption of C atoms on the surface of the Ir substrate is more stable than that on the bulk phase,which indicates that diamond nucleation can only occur on the substrate surface.The number of C atoms of sp3 hybridization in the amorphous hydrogenated carbon layer increases firstly and then decreases with the increase of ion kinetic energy under ion bombardment,confirming the existence of the ion kinetic energy or bias voltage window in the high-density nucleation of diamond.The interfacial binding energy is the lowest(about–0.58 eV/C)when diamond is epitaxially grown along the Ir substrate,meaning that the interface binding energy is the decisive thermodynamic factor for the epitaxial growth.In conclusion,this study clarifies the thermodynamic mechanism of single crystal diamond epitaxial growth under the bias-assisted ion bombardment,and points out a great significant guidance for the growth of diamond and other carbon based semiconductors.
作者
王伟华
张磊宁
丁峰
代兵
韩杰才
朱嘉琦
贾怡
杨宇
WANG Weihua;ZHANG Leining;DING Feng;DAI Bing;HAN Jiecai;ZHU Jiaqi;JIA Yi;Yang Yu(China Aerospace Science and Technology Innovation Research Institute,China Aerospace Science and Technology Corporation,Beijing 100176,China;School of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 102488,China;Faculty of Materials Science and Engineering/Institute of Technology for Carbon Neutrality,Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,China;National Key Laboratory of Special Environment of Composite Technology,Harbin Institute of Technology,Harbin 150001,China;Beijing Institute of Control Engineering,Beijing 100190,China)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2024年第4期416-422,共7页
Journal of Inorganic Materials
基金
国家重点研发计划(2020YFA0709700,2016YFE0201600)
国家自然科学基金(52072087)
广东省重点研发计划(2020B010169002)
黑龙江省自然科学基金(YQ2020E008)
中央高校基本科研业务费专项资金(HIT.OCEF.2022048)。
关键词
金刚石
异质外延
形核生长
第一性原理
结合能
diamond
heteroepitaxy
nucleation and growth
first-principle
binding energy
