In situ proximity gap monitor for lithography

摘要

A method and a system for implementing the method for determining an exposure gap between a mask and a resist material are provided. A first gratings is provided on one or more sides of a first structure defined by one or more first regions of the mask. A second gratings is provided on one or more sides of a second structure defined be one or more second regions of the mask. The first and the second structures are exposed to incident energy and the difference between a location in the first structure and a location in the second structure is measured. The exposure zap is extrapolated from the difference. The first and second structures are provided on the mask. The first gratings and the second gratings is provided by a mask writing tool.