Effects of highfrequency coil step on distribution of magnetic field in floatzone furnace

CAO Jianwei, FU Linjian, SHEN Wenjie, ZHU Liang, ZHANG Jun, SHI Gang,OUYANG Penggen, YE Xin, QIU Minxiu

(Zhejiang Jingsheng M&E Co., Ltd., Shangyu 312300, China)

Abstract: Float zone（FZ） method is one of the most important methods of growing monocrystalline silicon. Aiming at the problem of “cold needle” which is caused by the uneven heat distribution on the melt surface of polycrystalline silicon during the process of growing monocrystalline silicon by FZ method,a numerical simulation of growing monocrystalline silicon was made by using the finite element method. The coil models with step and without step were built to analyze the magnetic field distribution and joule heat distribution around the melting zone.The results indicate that the structure of highfrequency heating coil directly affects the distribution of the magnetic field around the melting zone, and then affects the distribution of generated joule heat. The step of the high frequency heating coil would result in a more uniform distribution of the magnetic field near the melting zone, and effectively solve the problem of “cold needle”.

Key words: float zone(FZ) method; coil step; numerical simulation