Patent attributes
Apparatus for processing substrates can include a gas distribution plate that includes an upper plate and a lower plate and a solid disk between the upper plate and the lower plate. Each of the upper plate and the lower plate has a central region and an outer region surrounding the central region, the central region being solid and the outer region having a plurality of through holes. The upper plate and the lower plate are coaxially aligned along a central axis extending through a center of the central region of the upper plate and a center of the central region of the lower plate. The solid disk is coaxially aligned with the upper plate and the lower plate. The solid disk is configured to block transmission of ultraviolet radiation through the solid disk.