Methods of measuring substrate properties, inspection apparatus, lithography systems, and device manufacturing methods

摘要

A method of measuring a property of a substrate, the substrate comprising a plurality of targets formed on the substrate, the method comprising measuring N of the plurality of targets using an optical measurement system, wherein N is greater than 2 A large integer and each of the N targets is measured Wt times and Wt is an integer greater than 2 to obtain N * Wt measurements; And determining R attribute values using Q equations and N * Wt measurements, wherein R Q ≦ N * Wt, and the optical measurement system has at least one changeable setting, For each of the N targets, a measurement value is obtained using different setting values of at least one changeable setting.