[15a-D411-1~11] 15.7 Crystal characterization, impurities and crystal defects

▲ [15a-D411-1] Application of Halbach array magnet on the Floating Zone Silicon

〇Xuefeng Han¹, Koichi Kakimoto¹, Kader Zaidat², Samah Alradi² (1.RIAM, Kyushu Univ., 2.Grenoble-Alpes Univ.)

Keywords:Floating zone, Simulation

Floating zone (FZ) silicon is widely used in the high-voltage power device because of its high purity. Previous study demonstrated that increasing the growth rate or diameter could increase the deflection of the solid-liquid interface [1]. More deflection of solid-liquid interface could introduce high thermal stress and lead to crack of single crystal. Therefore, we propose to use Halbach array magnet in the vicinity of three-phase line to improve the deflection of solid-liquid interface. To investigate the effect of Halbach array magnet on the deflection of solid-liquid interface, numerical simulations are conducted in three dimensions considering high-frequency electromagnetic (HF-EM) field, static magnetic field, fluid flow and heat transfer. The simulation model is constructed and performed using OpenFOAM [2]. Fig. 1 shows schematic diagram of the FZ process with Halbach array magnet (red color). The Halbach array magnet induces a relatively strong inward magnetic field and relatively weak outward magnetic field. In the vicinity of the solid-liquid interface, the melt flow toward the center is damped under the effect of the Lorentz force. Fig. 2 shows the comparison of deflection of solid-liquid interface between the calculation results with and without Halbach array magnet. The calculation results demonstrate that the application of Halbach array magnet could improve the deflection of solid-liquid interface.
Reference
[1] I. Drikis, M. Plate, J. Sennikovs, J. Virbulis, Journal of Crystal Growth, 474 (2017) 8-15.
[2] X.-F. Han, X. Liu, S. Nakano, H. Harada, Y. Miyamura, K. Kakimoto, Journal of Crystal Growth, (2019) 125403.
Acknowledgement
This work was partly supported by the New Energy and Industrial Technology Development Organization (NEDO) under the Ministry of Economy, Trade and Industry (METI)