METHOD FOR PREPARING POLYCRYSTALLINE SILICON INGOT

摘要

Disclosed is a method for preparing polycrystalline silicon ingot. The preparation method comprises: randomly laying seed crystals with unlimited crystal orientation at the bottom of crucible to form a layer of seed crystals and obtaining disordered crystalline orientations; providing molten silicon above the layer of seed crystals, controlling the temperature at the bottom of the crucible, making the layer of seed crystals not completely melted; controlling the temperature inside the crucible, making the molten silicon growing above the seed crystals, the molten silicon inheriting the structure of the seed crystals, then obtaining polycrystalline silicon ingot. By adopting the preparation method, a desirable initial nucleus can be obtained for a polycrystalline silicon ingot, so as to reduce dislocation multiplication during the growth of the polycrystalline silicon ingot.

主权项

1. A method for preparing polycrystalline silicon ingot, comprising:
(1) randomly laying seed crystals with unlimited crystal orientation at the bottom of crucible to form a layer of seed crystals and obtaining disordered crystalline orientations; (2) providing molten silicon above the layer of seed crystals, controlling the temperature at the bottom of the crucible below melting point of the seed crystals, making the layer of seed crystals not completely melted; (3) controlling the temperature inside the crucible, the temperature raising along the direction perpendicular to the bottom of the crucible to form temperature gradient, making the molten silicon growing above the seed crystals, the molten silicon inheriting the structure of the seed crystals, then obtaining polycrystalline silicon ingot.