Metrology method and apparatus, and device manufacturing method
US9069264B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 2012 |
| Grant date | Jun 30, 2015 |
| Priority date | — |
| Expiry date | Dec 24, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70683
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A target structure including a periodic structure is formed on a substrate. An image of the target structure is detected while illuminating the target structure with a beam of radiation, the image being formed using a first part of non-zero order diffracted radiation while excluding zero order diffracted radiation. Intensity values extracted from a region of interest within the image are used to determine a property of the periodic structure. A processing unit recognizes locations of a plurality of boundary features in the image of the target structure to identify regions of interest. The number of boundary features in each direction is at least twice a number of boundaries of periodic structures within the target structure. The accuracy of locating the region is greater than by recognizing only the boundaries of the periodic structure(s).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.