Determining an edge roughness parameter of a periodic structure
US10725387B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 2018 |
| Grant date | Jul 28, 2020 |
| Priority date | — |
| Expiry date | Jul 6, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2210/56
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a method of determining an edge roughness parameter of a periodic structure, the periodic structure is illuminated (602) in an inspection apparatus. The illumination radiation beam may comprise radiation with a wavelength in the range 1 nm to 100 nm. A scattering signal (604) is obtained from a radiation beam scattered from the periodic structure. The scattering signal comprises a scattering intensity signal that is obtained by detecting an image of a far-field diffraction pattern in the inspection apparatus. An edge roughness parameter, such as Lined Edge Roughness and/or Line Width Roughness is determined (606) based on a distribution of the scattering intensity signal around a non-specular diffraction order. This may be done for example using a peak broadening model.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.