To investigate interface shape and thermal stress during sapphire single crystal growth by the Cz method

• Published in: Journal of crystal growth Vol. 363; pp. 25 - 32
• Main Authors: Fang, H.S., Pan, Y.Y., Zheng, L.L., Zhang, Q.J., Wang, S., Jin, Z.L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2013; Elsevier
• Subjects: A1. Computer simulation; A1. Interface; A1. Stresses; A2. Czochralski method; B1. Sapphire; Cross-disciplinary physics: materials science; rheology; Crystal defects; Crystals; Exact sciences and technology; Growth from melts; zone melting and refining; Insulation; Materials science; Mathematical models; Methods of crystal growth; physics of crystal growth; Physics; Sapphire; Single crystals; Stresses; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Thermal stresses; B1. Sapphire; A1. Computer simulation; A1. Interface; A2. Czochralski method; A1. Stresses; Crystal growth; Liquid solid interface; Growth interface; Theoretical study; Czochralski method; Computerized simulation; Crystal perfection; Monocrystals; Sapphire; Growth mechanism; Stress effects; Modelling; Thermal stresses; Heat transfer; Crystal growth from melts
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2012.09.050

Global modeling is performed to predict electromagnetic field, heat transfer, melt flow, solid/liquid (S/L) interface shape, and thermal stress during RF-heated Czochralski (Cz) single crystal growth of sapphire. The relations between the convexity of the S/L interface and growth parameters, i.e., crystal rotation rate, crystal size, furnace insulation, and RF coil, are established. Thermal stress is represented by the von Mises stress, and the stress status in the growing crystal is characterized by the maximum von Mises stress. The curves regarding growth parameters and the maximum von Mises stress are obtained. According to the analysis, a flat or slightly convex S/L interface could be achieved by modifying the growth parameters, and the crystal quality could be improved by reducing thermal stress and its related defects. ► The relationship between the convexity of the S/L interface and growth parameters is obtained. ► The stress status in the growing crystal is evaluated by the von Mises stress. ► The curves regarding growth parameters and the maximum von Mises stress are achieved.