Apparatus made of silica for semiconductor device fabrication

Abstract

In a apparatus made of silica such as a heating furnace, a wafer basket, stick or the like used for semiconductor device fabrication, a first silica layer on the side faced to a semiconductor wafer contains a large amount of the OH group, and a second silica layer on the opposed side contains a small amount of the OH group. With this structure, it is possible to reduce the amount of impurities released through the first silica layer, and to suppress the deformation of the apparatus by the second silica layer. Also, by holding a third silica layer between the first and second silica layers, it is possible to further reduce the amount of impurities released from the first silica layer.

Dependencies are inferred from the claim text.