High aspect ratio clamp

摘要

The disclosure relates to a method and apparatus for protecting the edge of a substrate (12) and securing the substrate to the support member (26) during processing. The arrangement provides minimal contact with the substrate and provides improved edge exclusion. Support tabs (56) extend inwardly from the lower roof surface (62) to support the apparatus on the substrate and the inner terminus of the apparatus approaches the edge of the substrate to provide the improved edge exclusion. A variable height lower roof surface (66, 68) is provided over the edge of the substrate to provide an effective roof aspect ratio (width of the roof : height of the roof above the substrate) over the edge of the substrate which reduces the likelihood that a bridging layer will form between the apparatus and the substrate or beyond the substrate. <IMAGE> <IMAGE>