In-situ x-ray measurements of defect generation and crystalline quality during PVT growth, cool down and post-growth annealing of SiC

寻找生长路径以减少PVT生长SiC中的缺陷仍然是大规模生产具有适当电子性能的晶圆材料的关键课题。由于在2000°C以上的温度下通过改良的Lely技术生长SiC所需的极端条件，晶体种植者基本上对生长过程本身结构质量的演变“视而不见”。这同样适用于晶体的冷却，这一过程本身可能对生长晶体的最终结构质量有重要影响。我们提出利用高能x射线衍射原位监测从晶种到最终晶体以及冷却到环境温度期间晶体质量缺陷的产生和发展。x射线实验将包括研究生长后钢锭退火对结构质量的影响。该项目的主要目标是确定形成SiC晶体缺陷的工艺参数制度，如温度和材料通量。

The search for growth routes to reduce the defects in PVT grown SiC remains a crucial topic for lange scale production of wafer material with appropriate electronic properties. Because of the extreme conditions needed to grow SiC by the modified Lely technique at temperatures above 2000 °C, crystal growers are essentially "blind" to the evolution of the structural quality during the growth process itself. The same holds true for the cool-down of the crystals, a process step which by its own may have an important influence on the final structural quality of the grown crystals. We propose to monitor the defect generation and development of the crystalline quality from the seed to the final crystal and during cool down to ambient temperature by high-energy x-ray diffraction in-situ. The x-ray experiments will include a study of the influence of post-growth ingot annealing on the structural quality. The main goal of this project is the identification of process parameter regimes such as temperature and material flux where defects in SiC crystals are formed.