Phase Field Models and Undestanding Interface Evolution at Crystal Growth Initial States
Published : 12 March 2020
The proposed research concerns modeling the physics of crystal growth involved in Vertical Gradient Freeze (VGF), a method that allows the manufacturing of large ingots for the semi-conductor industry. In this process, the material is molten then solidifies as the temperature is slowly decreased with spatially controlled temperature profiles, in order to favor the orientation and the low defect density of the resulting crystal.
One of the main objectives of this project is to design numerical models that could provide an accurate description of the evolution of the liquid-solid interface in a II-VI alloy at the early stages of a crystal growth, so as to gain understanding of how one could control the system thermal state evolution and improve the quality of the crystallization. In particular, an approach based on phase field approximations of the solidification front will be developed. From the numerical point of view, such representation of the front should allow a more robust modeling of topology and phase changes, while also providing insight on the relevant relationships between the mesoscopic and macroscopic scales.
Underlying experimental and industrial goals are also to help scientists analyze the process observable signals and determine the optimal conditions that need to be setup in order to achieve desired material properties.