| 摘要 |
A chemical barrier is disclosed for use in minimizing the extent of reaction between silica, SiO2, originating from a silica container and carbon, C, originating from a graphite support vessel supporting the container during production of single crystal silicon by a Czochralski-type process. The chemical barriers are preferably substantially non-reacting with respect to both silica and carbon. To the extent the chemical barriers react with silica and/or carbon, the reaction products include only stable, substantially non-reactive solids or alternatively, such solids with a relatively small amount of gases. Preferred materials suitable for use in the chemical barriers of the present invention (alone, as heterogeneous mixtures or as composite layers) include metals and/or metal oxides in contact with the outer surface of a silica container and metals, metal oxides and/or metal carbides in contact with the outer surface of a graphite support vessel. The chemical barriers of the present invention can be applied by forming a layer of barrier material, for example, by depositing or coating the barrier material to the inner surface of the silica container and/or to the outer surface of the graphite support vessel. Alternatively, the barrier can be applied as a thin foil, film or other sheet placed between the appropriate surfaces of the silica container and graphite support vessel.
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