中文摘要：

6H-SiC 单身者晶体被升华方法种。外国谷物在晶体的方面上经常发生，这被发现。描绘外国谷物，一纵并且部分切割样品被标准机械处理准备方法。拉曼光谱证实外国谷物实际上是 mis 面向的 6H-SiC 谷物。外国谷物的表面结构被化学蚀刻和光显微镜学学习。在外国谷物区域蚀刻坑，这被显示出拿等腰的三角的形状，它与在叠差错的单音水晶的区域，和高密度的那些不同在外国谷物的表面上被观察。外国谷物表面的取向决心是(10 $\bar 1 $ 4 ) 由 back-scattering X 光检查 Laue 的飞机图象。X 光检查粉末衍射表明粉末是部分在长水晶生长跑以后的 graphitized。因此， Si 的损失导致 C 包括的形成，这被相信，它为在方面区域的外国谷物的成核负责。

英文摘要：

6H-SiC single crystals were grown by sublimation method. It is found that foreign grains occur frequently on the facets of the crystals. To characterize the foreign grain, a longitudinal and a sectional cut samples were prepared by standard mechanical processing method. Raman spectrum confirms that the foreign grain is actually a mis-oriented 6H-SiC grain. The surface structure of the foreign grain was studied by chemical etching and optical microscopy. It is shown that etch pits in foreign grain region take the shape of isosceles triangle, which are different from those in mono-crystalline region, and high density stacking faults are observed on the surface of the foreign grain. The orientation of foreign grain surface is determined to be （10]-4） plane by back-scattering X-ray Laue image. The X-ray powder diffraction reveals that the powder is partly graphitized after a long crystal growth rim. Therefore it is believed that the loss of Si results in the formation of C inclusions, which is responsible for the nucleation of foreign grain in the facet region.