TEST STRUCTURE DESIGN FOR METROLOGY MEASUREMENTS IN PATTERNED SAMPLES

摘要

A test structure is presented for use in metrology measurements of a sample pattern formed by periodicity of unit cells, each formed of pattern features arranged in a spaced-apart relationship along a pattern axis. The test structure comprises a test pattern, which is formed by a main pattern which includes main pattern features of one or more of the unit cells and has a symmetry plane, and a predetermined auxiliary pattern including at least two spaced apart auxiliary features located within at least some features of the main pattern, parameters of which are to be controlled during metrology measurements.