Enhancing metrology target information content
US11085754B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 2018 |
| Grant date | Aug 10, 2021 |
| Priority date | — |
| Expiry date | Jun 13, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2210/56
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Metrology targets designs, design methods and measurement methods are provided, which reduce noise and enhance measurement accuracy. Disclosed targets comprise an additional periodic structure which is orthogonal to the measurement direction along which given target structures are periodic. For example, in addition to two or more periodic structures along each measurement direction in imaging or scatterometry targets, a third, orthogonal periodic structure may be introduced, which provides additional information in the orthogonal direction, can be used to reduce noise, enhances accuracy and enables the application of machine learning algorithms to further enhance accuracy. Signals may be analyzed slice-wise with respect to the orthogonal periodic structure, which can be integrated in a process compatible manner in both imaging and scatterometry targets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.