Bell of translucent fused silica for the precipitation of polysilicon

Abstract

Bell of translucent fused silica having an inner layer of transparent fused silica for the precipitation of polysilicon. The thickness of the transparent fused silica layer increases continuously towards the open end of the bell while the total wall thickness of the bell is kept constant. The thickness increase of the transparent fused silica layer begins preferably beyond the center of the total length of the bell. The thickness of the transparent fused silica layer increases by at least half of the thickness which it has in the top part of the bell.

Dependencies are inferred from the claim text.