Abstract:
In a lithographic process product units such as semiconductor wafers are subjected to lithographic patterning operations and chemical and physical processing operations. Alignment data or other measurements are made at stages during the performance of the process to obtain object data representing positional deviation or other parameters measured at points spatially distributed across each wafer. This object data is used to obtain diagnostic information by performing a multivariate analysis to decompose the set of said vectors representing the wafers in said multidimensional space into one or more component vectors. Diagnostic information about the industrial process is extracted using said component vectors. The performance of the industrial process for subsequent product units can be controlled based on the extracted diagnostic information.
Abstract:
Disclosed is a method of correcting an image characteristic of a substrate onto which one or more product features have been formed using a lithographic process, and an associated inspection apparatus method. The method comprises measuring an error in said image characteristic of said substrate; and determining corrections for a subsequent formation of the product features based upon the measured error and a characteristic of one or more of said product feature(s).