Study on growth condition of the large flattened diamond crystals with high quality

高品质大扁平金刚石晶体生长条件研究

基本信息

批准号：
09650769
负责人：
HIROSE Yoichi
金额：
$ 1.73万
依托单位：
Tokai university
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650769/
关键词：
diamond CVD diamond flattened diamond nucleation combusion flame Raman spectroscopy high quality diamond synthesis ダイヤモンド偏光結晶面

项目摘要

Flattened diamond crystals synthesized by CVD have very flat surfaces, good crystallinity and contain defects in low density. If large flattened diamond crystals (e.g.1 mm diameter) can be synthesized, many application, for example, semiconductor substrates and heat sinks, are expected. In this report, the author describes an investigation of the most suitable synthesis condition and growth mechanism of the flattened diamond crystals.Growth experimentThe substrate temperature in the nucleation stage plays an important in the yield of the flattened diamond crystals. When the substrate temperature is kept at 500 during the nucleation stage, the yield of flattened diamond crystals is higher than when the substrate temperature is kept constant at 750 . The copper substrate is the most suitable material for the synthesis of the flattened diamond crystals. Based on SEM observations, it was determined that approximately 90% of the diamond crystals show flattened morphology under optimum conditions.Growth mechanismIn the first stage of crystal growth, texture growth nucleation occurred with {111}-oriented surfaces, and twin boundaries parallel to {111} and thus to the substrate surface appear. Due to the presence of re-entrant corners along multiple twin-boundaries, the pre-ferential growth of side faces takes place in six directions, leading to the formation of flattened diamond crystals.

CVD合成的扁平金刚石晶体具有非常平坦的表面、良好的结晶度和低密度的缺陷。如果可以合成大的扁平金刚石晶体（例如直径 1 毫米），则有望实现许多应用，例如半导体基板和散热器。在本报告中，作者描述了对扁平金刚石晶体最合适的合成条件和生长机制的研究。生长实验成核阶段的基底温度对于扁平金刚石晶体的产率起着重要作用。当成核阶段基底温度保持在500℃时，扁平金刚石晶体的产率比基底温度恒定在750℃时更高。铜基材是最适合合成扁平金刚石晶体的材料。基于SEM观察，确定在最佳条件下大约90%的金刚石晶体呈现扁平形貌。生长机制在晶体生长的第一阶段，{111}取向的表面发生织构生长成核，孪晶边界平行于{ 111}并由此在基材表面上出现。由于沿多个孪晶界存在凹角，侧面会在六个方向上优先生长，从而形成扁平金刚石晶体。