Advances of interface, flow, and stress control for VB crystal growth: An overview

Abstract

The Vertical Bridgman (VB) method plays a vital role in growing crystals of Group II-VI semiconductors, oxides, and fluorides. However, achieving large-scale crystals with high quality remains challenging due to the complexities of heat-mass transfer and phase change phenomena involved in the process. To enhance the understanding and control of the VB crystal growth, this paper reviews previous numerical simulation studies on optimizing and controlling the melt-crystal interface, flow, and stress during the growth process, as these factors strongly influence the generation and distribution of defects. The shape of the melt-crystal interface significantly impacts the propagation of grains and inclusions, and a desirable interface can be achieved by enhancing axial heat flux or suppressing radial heat dissipation at the interface. Effective control of melt flow ensures uniform solute distribution, and strategies like suppressing natural convection or introducing forced convection techniques are prove beneficial. Stress plays a pivotal role in dislocation movement and interaction, potentially leading to low angle grain boundaries and cracks. Stress control methods focus on minimizing deformation sources, including temperature, concentration, and mechanical contact. The paper provides detailed explanations of interface, flow, and stress control methods, offering valuable insights for researchers aiming to grow large-scale, high-quality crystals with enhanced efficiency. Furthermore, the control mechanisms and methods discussed in this review may also be applicable to other melt crystal growth techniques.