| 摘要 |
Embodiments in accordance with the present invention relate to various techniques which may be employed alone or in combination, to reduce or eliminate the deposition of material on the bevel of a semiconductor workpiece (882). In one approach, a shadow ring (880) overlies the edge of the substrate (882) to impede the flow of gases to bevel regions. The geometric feature at the edge (880a) of the shadow ring directs the flow of gases toward the wafer in order to maintain thickness uniformity across the wafer while shadowing the edge. In another approach, a substrate heater/support is configured to flow purge gases to the edge of a substrate being supported. These purge gases prevent process gases from reaching the substrate edge and depositing material on bevel regions.
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