Patent Document ID: 9851300
Application ID: 14678411
Patent Flag: 1

Claim One:
1. An angle-resolved reflectometer comprising: a coherent light source; an optical system including at least one of: a detector configured to measure light from a collected pupil of the optical system, a coherent light source, a control unit, an optical scanning unit, or a mechanical scanning unit, wherein the optical system is configured to scan a target pattern according to a scanning pattern using a spot of coherent light from the coherent light source to yield a plurality of scans associated with light distribution in a collected pupil, wherein the spot covers a part of the target pattern; and one or more processing units communicatively coupled to the optical system, wherein the one or more processing units are configured to execute a set of program instructions stored in memory, wherein the program instructions are configured to cause the one or more processing units to: receive a plurality of scans associated with a light distribution in the collected pupil of the optical system from the detector; derive an overlay linear response to at least one non-periodic effect based on at least one of an overlay value, a misalignment vector, or an overlay linear response vector; and estimate a corrected overlay value based on the derived overlay linear response to at least one non-periodic effect.