CMP effects on manufacturability are becoming more prominent as we move towards advanced process nodes, 28nm and below. It is well known that dishing and erosion occur during CMP process, and they strongly depend on pattern density, line spacing and line width [1]. Excessive thickness or topography variations can lead to shrinkage of process windows, causing potential yield problems such as resist lifting or printability issues. When critical patterns fall into regions with extreme topography variations, they would be more sensitive to defects and could potentially become yield limiters or killers. Scanner tools compensate and correct topography variations by following the given profile [2]. However the scanner exposure window size is wider compared to local topography variations in design. This difference would generate new lithography focus sensitive weak points which may be missed. Experiments have been conducted as shown in Fig 1. Design under manufacturing has been subjected to scanner tool topography focus corrections. Despite of the corrections, Site B topography height has worsened while site A and C shown some improvements. As a result, additional improvements need to be done to meet manufacturability requirements.
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