Metrology method and apparatus, computer program and lithographic system
US10191391B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 2016 |
| Grant date | Jan 29, 2019 |
| Priority date | — |
| Expiry date | Sep 29, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70633
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is a metrology apparatus for measuring a parameter of a lithographic process, and associated computer program and method. The metrology apparatus comprises an optical system for measuring a target on a substrate by illuminating the target with measurement radiation and detecting the measurement radiation scattered by the target; and an array of lenses. Each lens of the array is operable to focus the scattered measurement radiation onto a sensor, said array of lenses thereby forming an image on the sensor which comprises a plurality of sub-images, each sub-image being formed by a corresponding lens of the array of lenses. The resulting plenoptic image comprises image plane information from the sub-images, wavefront distortion information (from the relative positions of the sub-images) and pupil information from the relative intensities of the sub-images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.