Numerical Simulation of Gallium Oxide Crystals Grown by Czochralski Method(2/3)

In recent years, the energy problem has become the focus of attention all over the world. The energy efficiency of electronic components is the focus of energy conservation. Electric vehicles, solar photovoltaic, wind power, etc. all use a lot of high-power devices. Gallium oxide (Ga2O3) has a wide energy band gap so that it can withstand high temperatures, and a high breakdown electric field enables it to withstand higher operating voltages. Compared to other wide band gap semiconductor materials such as SiC and GaN, Ga2O3 can grow from the liquid phase. Hence, the crystal growth rate is faster and it is easier to grow large sizes with a higher quality. The Czochralski crystal growth method is commonly used for growing the Ga2O3 crystal. During the growth of Ga2O3 crystal, the radiation characteristics inside the crystal will affect the radiative cooling with the furnace wall, the shape of the solid-liquid interface, and then the shape of the crystal. The thermal stress in the crystal is also affected by the shape of the crystal. In order to avoid the possibility of unstable spiral crystals during the growth process, it is important to understand the evolution of the solid-liquid interface, crystal shape, thermal and flow fields, and thermal stress in the crystal during the growth process. This study will combine 2D axisymmetric and 3D mixed simulation modes to fully simulate the crystal growth from the crown to the crystal body, and observe the effects of high temperature oxygen decomposition and free carrier thermal radiation absorption on crystal growth. The flow behavior, temperature and thermal stress distributions of the molten melt at various stages will be investigated. The results of this research are expected to understand the principle and mechanism of Ga2O3 crystal growth and establish the thermal environment conditions for Ga2O3 crystal growth.