Finite Element Simulations Facilitate Double-Seeds Technology to Grow High-Quality Aln Crystal

Abstract

Aluminum nitride (AlN) is one of the representatives of the third-generation semiconductor, and its excellent characteristics have gradually attracted attention. However, the higher growth difficulty limits the application of AlN crystal in optoelectronic devices, which is mainly attributed to the lack of large-size and high-quality AlN seeds. This study innovatively placed double seeds on the surface of the AlN source (seed 1) and the top of the crucible (seed 2) for growth. The simulation results show that the AlN source (seed 1) has a higher temperature (2586K), and the grown AlN crystals have lower stress and fewer dislocations, while the growth rate is slower (30um/h). The temperature at the top of the crucible top (seed 2) is lower (2542K) and the growth rate is faster (1000um/h), however, the growing AlN crystals have high stress and are prone to cracking. The experimental results are consistent with the simulation results. The FWHM of AlN crystal grown by seed 1 is only 43 arcsec, which can be used as the optimal solution for cultivating high-quality seeds. This work provides a pathway for the growth of high-quality AlN crystals.

Keywords: PVT, AlN, crystal growth, high-quality, double seeds