Title: Production of semiconductor grade silicon sphere from metallurgical silicon particles using air ambient
Application Number: 86100377 Application Date: 1986.02.15
Publication Number: 1012909 Publication Date: 1987.08.26
Approval Pub. Date: Granted Pub. Date: 2001.02.14
International Classifi-cation: C30B29/60
Applicant(s) Name: Taxas Instruments Inc. (US) 13500 North Central Ex Address:
Inventor(s) Name: Jules D. Levine
Attorney & Agent: YAN CHENGGEN
Abstract:
     This invention deals with a method in which the metallurgical silicon is used to manufacture the single-crystal silicon sphere of solar cell grade used for solar cells. The method is as follows: the metallurgical silicon particles are screened to a required range and their outer surfaces are oxidized in the air to form an oxidized surface layers, then the particles are heated in the air and the silicon underneath the surface layer is smelted, thus the impurity moves toward the surface layer, finally, the surface layer and impurity are corroded away. For the remains of these particles, the procedure mentioned above is repeated until the purity of silicon reaches the required level. An intermediate shot step can be used to produce the sphere bodies which have basically uniform diameters and can be used as raw materials in the repeating cycles.
Time: 7
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