Crystallization behavior and defect analysis on induction growth of hexagonal GaN in isothermal relaxation

Abstract

Gallium nitride (GaN) plays a vital role in the devices of many fields, including communication, display, and lighting. The key to fabricating high-performance GaN devices lies in the growth quality of GaN, exploring the growth mechanism is crucial. In this study, molecular dynamics was used to simulate the induced crystallization processes of wurtzite crystals of GaN based on solid-liquid models. Additionally, the results were studied using a variety of methods for investigating its growth mechanism and perform defect analysis. The results show that the qualities of the crystal growth at low temperatures are not optimal, with a high density of defective atoms and dislocations density, and disordered structures form. The lamellar structure with the overlapping arrangement of the wurtzite and zinc-blende structures forms at high temperatures, where the crystal growth quality is better than that at low temperatures. Dislocation and void defects are observed in the system, however, the number of these two defects changes in opposite trends during the relaxation process. Void defects are more conducive to structural stability than the formation of dislocations and the random arrangement of disordered atoms. This research can contribute to a further understanding of the crystal formation of GaN.