Focus monitoring method using asymmetry embedded imaging target
US9466100B2 · kind B2 · utility
1Cited by
7References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 3, 2013 |
| Grant date | Oct 11, 2016 |
| Priority date | — |
| Expiry date | Jun 3, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30168
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for monitoring mask focus includes measuring profile asymmetries in a target feature including sub-resolution assist features and deriving a focus response based on a known correlation between the profile and focus of a corresponding mask. A computer system in a lithographic process may adjust mask focus based on such derived information to conform to a desired fabrication process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.