掺杂和不同降温条件下合成金刚石的晶体缺陷分析

发布时间：2018-05-07 23:23

本文选题：合成金刚石 + 温控条件　；参考：《燕山大学》2015年硕士论文

【摘要】：本文利用同步辐射白光貌相术、傅里叶变换红外光谱仪、显微共焦拉曼光谱仪、扫描电子显微镜等仪器研究了慢升温恒温保持慢降温(SCS)、慢升温恒温保持快降温(SCQ)、慢升温恒温保持骤停(SCQQ)三组不同温控条件下合成的金刚石晶体。分析了三组样品晶体内部所含杂质种类、晶体缺陷类型、空间分布特点、缺陷的分布特点与晶体掺杂的关系,结合晶体的合成条件,分析了晶体缺陷与不同降温速率的关系。傅里叶变换红外光谱结果显示,第一组SCS样品除含有氢、氮等杂质外,还含有磷、硼等掺杂元素。由同步辐射白光貌相术得到的衍射图像表明,三组合成晶体中缺陷的主要表现形式是位错、扇形层错和其他面缺陷。第一组合成样品中,主要掺入磷杂质的样品D16-6在晶体表层560~630μm范围内出现了密度较大的位错层,位错走向在111~112之间。结合红外图谱,发现该位错层空间分布与磷的分布范围相吻合。主要掺入硼杂质的样品D16-4在晶体表层580~690μm范围内出现了位错密度较大的位错层,但位错层衍射衬度比D16-6的位错层衬度小。同时掺杂磷和硼的金刚石样品则在晶体表层600~760μm范围内出现了位错密度较大的位错层,且位错层的位错像衬度与掺磷为主样品的位错像衬度相当。在第二组和第三组样品中除了同生位错、层错等缺陷之外,还出现了切割同生位错的面缺陷。这种面缺陷在第二组样品中仅在局部零星出现,大多平行于{100},在第三组样品中则多个平行成组出现,面缺陷间密度较大,间距在68~86μm之间。这些面缺陷方位介于{110}~{113}之间。由于这些面缺陷切割了位错和层错等同生缺陷,说明它们形成于这些同生缺陷之后,也证明了这些面缺陷是晶体快速降温引起。由于这些面缺陷在SCQQ样品中比SCQ样品中发育更多,表明快速和骤停降温过程对合成金刚石的质量造成了不良影响。
[Abstract]:In this paper, synchrotron radiation white light profiling, Fourier transform infrared spectrometer, microconfocal Raman spectrometer, Three groups of diamond crystals have been studied by scanning electron microscope (SEM) under different temperature-controlled conditions: slow temperature constant temperature keeping slow cooling temperature keeping fast temperature drop and slow temperature constant temperature keeping sudden arrest (SCQQ). The types of impurities, the types of crystal defects, the spatial distribution characteristics, the relationship between the distribution characteristics of defects and crystal doping in three groups of samples were analyzed. The relationship between the crystal defects and different cooling rates was analyzed in combination with the synthesis conditions of the crystals. Fourier transform infrared spectroscopy (FTIR) showed that the first group of SCS samples contained not only impurities such as hydrogen and nitrogen, but also doping elements such as phosphorus and boron. The diffraction images obtained by synchrotron radiation white light profiling show that the main forms of defects in the three crystals are dislocations, sector faults and other surface defects. In the first combinatorial sample, the sample D16-6, which is mainly doped with phosphorus impurity, has a dense dislocation layer in the range of 560,630 渭 m on the surface of the crystal, and the dislocation strike is between 111 and 112. Combined with infrared spectra, it was found that the spatial distribution of the dislocation layer coincided with the distribution range of phosphorus. The sample D16-4 mainly doped with boron impurity appears dislocation layer with high dislocation density in the range of 580U 690 渭 m on the surface of crystal, but the diffraction contrast of dislocation layer is smaller than that of D16-6. At the same time, the diamond samples doped with phosphorus and boron have a high dislocation density in the range of 600 ~ 760 渭 m on the surface of the crystal, and the dislocation contrast of the dislocation layer is equivalent to that of the phosphorus doped diamond sample. In the second group and the third group, in addition to the dislocations, stacking faults and other defects, there are also dislocations in the cutting surface. In the second group of samples, most of them are parallel to {100}, and in the third group there are many parallel groups. The density of surface defects is high, and the distance between them is between 68 ~ 86 渭 m. The azimuth of these surface defects is between {110} and {113}. The dislocations and stacking faults are cut by these surface defects, which indicates that they are formed after these syngenic defects, and it is also proved that these surface defects are caused by the rapid cooling of crystals. Because these surface defects are more developed in SCQQ samples than in SCQ samples, it is suggested that the rapid and sudden cooling process has a negative effect on the quality of synthetic diamond.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ163

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