Characterization of foreign grain on 6H-SiC facet  

作　　者：王英民 李娟 宁丽娜 高玉强 胡小波 徐现刚 

机构地区：[1]State Key Laboratory of Crystal Materials,Shandong University

出　　处：《Journal of Central South University》2009年第3期344-348,共5页中南大学学报（英文版）

基　　金：Projects(2006AA03A145,2007AA03Z405) supported by the National High-Tech Research and Development Program of China;Projects(50721002,50802053) supported by the National Natural Science Foundation of China;Project (707039) supported by the Cultivation Fund of the Key Scientific and Technical Innovation Project,Ministry of Education of China

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.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 ( 104) 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 run. 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.

关 键 词：6H-SIC surface morphology foreign grain sublimation method 

分 类 号：O76[理学—晶体学]