衬底用单晶金刚石晶格随温度变化的研究

本文对CVD(Chemical Vapour Deposition,CVD)外延生长中作为衬底的高温高压(HTHP)单晶金刚石进行拉曼光谱测试,利用谱峰半高宽(FWHM)判断了衬底的结晶质量.开展了升温(室温～1000℃)和降温(1000℃ ～室温)过程中衬底晶格变化的X射线原位测量研究.实验表明:衬底的晶格常数随温度...

Temperature-Depending Variation of Lattice of Single Crystal Diamond as Substrate

The Raman spectrum test was performed on the high temperature and high pressure (HTHP) single crystal diamond as the candidates of the substrates in the CVD(Chemical Vapour Deposition, CVD) epitaxial growth, and the crystalline quality of the substrates was judged by the full width at half maximum (FWHM) of the peak. X-ray in-situ measurement study of the substrate lattice changes during the heating (room temperature to 1 000 ℃) and cooling (1 000 ℃ to room temperature) processes. Experiments show that the lattice constant of the substrate changes with temperature, and the stress caused by the lattice change at 1 000 ℃ is close to the GPa level. The lattice constant is larger in the cooling process than in the heating process, and the same phenomenon is found in the calculation result of the linear expansion coefficient. According to the FT-IR test results of the tested sample, it is inferred that the reason for the variant above-mentioned lattice change is the difference in nitrogen content in the sample. The higher the nitrogen content, the larger the FWHM of the Raman spectrum, and the lattice constant of substrate more obvious changes with temperature, the larger the linear expansion coefficient.