| 引用本文: | 刘俊杰,关春龙,杨国永,易剑,刘帅伟,王祥兵,宋惠,江南,西村一仁.拼接法制备单晶金刚石的拼接缝形貌与残余应力[J].中国表面工程,2024,37(6):247~256 |
| LIU Junjie,GUAN Chunlong,YANG Guoyong,YI Jian,LIU Shuaiwei,WANG Xiangbing,SONG Hui,JIANG Nan,KAZUHITO Nishimura.Stitched Seam Morphology and Residual Stress of Single-crystal Diamond Prepared by Splicing Method[J].China Surface Engineering,2024,37(6):247~256 |
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| 摘要: |
| 金刚石材料作为功能性新材料之一，具有超高的禁带宽度和高的热导率，被誉为“终极半导体”。受到学术界和工业界的广泛关注，然而受制于金刚石的沉积机理，英寸级、高品质单晶金刚石暂未实现低成本制备。为了解决半导体领域所需的单晶金刚石在大尺寸、高品质方面受到的限制，利用 15 kW 微波等离子体化学气相沉积（MPCVD）设备，采用拼接法制备了大尺寸单晶金刚石，研究了拼接界面角度对拼接缝微观形貌与应力的影响。利用激光共聚焦显微镜（CLSM）以及扫描电镜（SEM）对沉积后的拼接缝进行微观形貌观察；利用拉曼光谱（Raman）和荧光光谱（PL）对沉积后的拼接缝进行表征及应力分析；利用透射电镜（TEM）对拼接缝的微观组织进行了结构表征。研究结果表明：采用 60°的拼接界面角度进行马赛克拼接沉积，制备的外延层在拼接缝更平滑，拼接缝处的残余应力最低，仅为 0.42 GPa。研究结果为大尺寸（英寸级）单晶金刚石基板的制备提供了一种研究方向。 |
| 关键词: 微波等离子体化学气相沉积法(MPCVD) 马赛克拼接 界面调控 同质外延 单晶金刚石 |
| DOI：10.11933/j.issn.1007-9289.20231230003 |
| 分类号:TQ163；O782 |
| 基金项目:宁波市重大科技攻关项目 (2021ZDYF020196, 2021ZDYF020198) |
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| Stitched Seam Morphology and Residual Stress of Single-crystal Diamond Prepared by Splicing Method |
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LIU Junjie1，2，GUAN Chunlong1，YANG Guoyong2，YI Jian2，LIU Shuaiwei1，2，WANG Xiangbing2，3，SONG Hui2，JIANG Nan2，KAZUHITO Nishimura2
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1.School of Material Science & Engineering, Henan University of Technology, Zhengzhou 450001 , China ；2.Key Laboratory of Advanced Marine Materials, Ningbo Institute of Materials Technology & Engineering,CAS, Ningbo 315201 , China ；3.School of Mechanical Engineering, Yangzhou University, Yangzhou 225127 , China
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| Abstract: |
| The diamond is known as the “ultimate semiconductor” because of its ultra-high bandgap width, high thermal conductivity, and excellent chemical and physical properties. Large-size single-crystal diamonds with low defect densities and ultra-smooth and ultra-flat surfaces have good application prospects in aerospace, semiconductor devices, and optical windows. One of the key factors to achieve industrial applications is meeting the size standards. A large number of studies have shown that the difficulty in limiting the preparation of high-quality, large-size single-crystal diamonds lies in the control of defects and the increase in the deposition rate. Restricted by the preparation mechanism, studies have shown that the mosaic splicing method is the most effective means of overcoming the size limit and realizing the preparation of large-size single-crystal diamond wafers. To address the limitations on quality and size, homogeneous epitaxial mosaic deposition was carried out with (100) oriented chemical vapor deposition (CVD) single-crystal diamonds as seed crystals using microwave plasma CVD equipment independently built by a laboratory. The effects of different splicing interface angles on the microstructure and residual stress of the splicing seam were studied by controlling the orientation and thickness of the two seed crystals used for splicing. The microstructure of the joints after deposition was observed using laser confocal microscopy and scanning electron microscopy. The structural characterization and stress analysis of the deposited joints were performed by Raman spectroscopy and fluorescence spectroscopy, respectively. The microstructure of the joints was characterized by transmission electron microscopy (TEM). The results show that the closer the edge angle of the diamond seed crystal used for deposition is to the plasma ball, the easier it is to be affected by the edge-discharge effect of the plasma and produce a relatively higher electric field, which improves the cracking ability of the gas in the reaction chamber and increases the concentration of the ionized plasma group. In addition, compared with the 90° splicing interface angle, the lap-splicing interface prepared at a certain tilt angle is covered by the seed crystal to a certain extent, which reduces the concentration of carbon-containing precursors entering the splicing seam for lateral deposition. Therefore, it is important to study the influence of the splicing interface angle on the preparation of large-size single-crystal diamonds by mosaic splicing. Mosaic splicing deposition was performed at a splicing interface angle of 60°. The prepared epitaxial layer was the most flat at the splicing joint, and the splicing deposition quality was high. The deposited epitaxial layer was relatively flat, thereby achieving the ideal splicing effect. No carbon atom shift due to mutual traction and extrusion were observed in the TEM samples. When there is compressive stress in the diamond crystal, the lattice vibration and scattering are enhanced, the spectrum is red-shifted, and the first-order Raman peak of the diamond is >1 332.5 cm?1 . When there is tensile stress in the diamond crystal, the lattice vibration and scattering are weakened, the spectrum is blue-shifted, and the first-order Raman peak of the diamond is <1 332.5 cm?1 . Therefore, the stress can be calculated according to the difference between the moving spectrum and standard value. Mosaic splicing deposition was performed at a 60°splicing interface angle. The residual stress at the splicing seam of the prepared epitaxial layer was the lowest at only 0.42 GPa. Compared with the 30° sample, the residual stress at the splicing seam was reduced by 10.39%. Compared with the 90° splicing sample, the residual stress at the splicing seam was reduced by 27.37%. This shows that using a certain angle to construct the splicing interface is more conducive to the preparation of large-size single-crystal diamond. This provides a research direction for the preparation of large-size single-crystal diamond substrates. |
| Key words: microwave plasma chemical vapor deposition (MPCVD) mosaic interface control homogeneous extension single crystal diamond |
