Local design of the hot-zone in an industrial seeded directional solidification furnace for quasi-single crystalline silicon ingots

To preserve the seed crystal in the melting process and improve the thermal field in the hot-zone during the solidification process aiding the formation of a quasi-single crystalline silicon ingot, an insulation partition block was designed for use in the hot-zone of an industrial seeded directional solidification furnace. A global model taking into account thermal conduction, thermal radiation, melt convection and argon flow was established to investigate the effects of the insulation configuration design on the thermal field, solidification interface shape, melt convection, argon recirculation and power consumption. In addition to comparing insulation configuration designs with and without the partition block, we carried out a comprehensive parameter study of the local design of the hot-zone, including the position, the width and the thickness of the insulation partition block. The results show that a suitable temperature gradient and a flat or slightly convex interface during seed preservation and bulk crystal growth can be achieved to maintain the quasi-single crystal structure all the way to the top of the silicon ingot. Furthermore, the argon recirculation and energy consumption can be reduced and the melt flow motion can be controlled by good insulation partition block design.

► Global modeling for quasi-single crystalline silicon growth was performed.
► We carried out a comprehensive parameter study of the local design of the hot-zone.
► A suitable thermal gradient and a flat or slightly convex interface can be achieved.
► The melt flow motion can be controlled by good insulation partition block design.
► The energy consumption can be reduced by good insulation partition block design.