Abstract:
PROBLEM TO BE SOLVED: To provide a method of improving the imaging of patterns having a small exposure latitude and/or improving exposure latitude without detriment to DOF (depth of focus). SOLUTION: In a lithographic device manufacturing method, sub-resolution assist features are provided to equalize the intensities of the diffraction orders that form the image of the pattern on a substrate. In the case of bright lines against a dark field used with a positive tone resist for forming trenches at or near resolution, the assist features may comprise narrow lines equidistantly between the feature lines. In this way, an improvement of exposure latitude may be obtained without reduction of DOF. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
In the measurement of properties of a wafer substrate, such as Critical Dimension or overlay a sampling plan is produced defined for measuring a property of a substrate, wherein the sampling plan comprises a plurality of sub-sampling plans. The sampling plan may be constrained to a predetermined fixed number of measurement points and is used to control an inspection apparatus to perform a plurality of measurements of the property of a plurality of substrates using different sub-sampling plans for respective substrates, optionally, the results are stacked to at least partially recompose the measurement results according to the sample plan.