Advanced process control methods for process-aware dimension targeting

摘要

Disclosed are methods of advanced process control (APC) for particular processes. A particular process (e.g., a photolithography or etch process) is performed on a wafer to create a pattern of features. A parameter is measured on a target feature and the value of the parameter is used for APC. However, instead of performing APC based directly on the actual parameter value, APC is performed based on an adjusted parameter value. Specifically, an offset amount (which is previously determined based on an average of a distribution of parameter values across all of the features) is applied to the actual parameter value to acquire an adjusted parameter value, which better represents the majority of features in the pattern. Performing this APC method minimizes dimension variations from pattern to pattern each time the same pattern is generated on another region of the same wafer or on a different wafer using the particular process.