Effect of 6H-SiC crystal growth shapes on thermo-elastic stress in the growing crystal

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2012-07, Vol.19 (7), p.622-627
• Main Authors: Shi, Yong-gui, Dai, Pei-yun, Yang, Jian-feng, Jin, Zhi-hao, Liu, Hu-lin
• Format: Article
• Language: English
• Subjects: 6H-SiC单晶; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Corrosion and Coatings; Crystal growth; Crystals; Deposition; Finite element method; Glass; Graphite; Growth chambers; Materials Science; Metallic Materials; Natural Materials; SiC晶体; Silicon carbide; Single crystals; Stress concentration; Stress distribution; Stresses; Surfaces and Interfaces; Thin Films; Transition layers; Tribology; 弹性应力分布; 数量级; 最大值; 有限元法; 热弹性应力; 生长形状
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-012-0604-4

The effect of 6H-SiC crystal growth shapes on the thermo-elastic stress distribution in the growing crystal was systematically in- vestigated by using a finite element method. The thermo-elastic stress distribution in the crystal with a flat growth shape was more homoge- neous than that in the crystals with concave and convex growth shapes, and the value of thermo-elasticity in the crystal with a fiat growth shape was also smaller than that in the two other types of crystals. The maximum values of thermo-elastic stress appeared at interfaces be- tween the crystal and the graphite lid. If the lid was of the same properties as 6H-SiC, the thermo-elastic stress would decrease in two orders of magnitude. Thus, to grow 6H-SiC single crystals of high quality, a transition layer of SiC formed by deposition or reaction is suggested; meanwhile the thermal field in the growth chamber should be adjusted to maintain the crystals with fiat growth shapes.