Determining profile parameters of a structure using approximation and fine diffraction models in optical metrology
US7949490B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2007 |
| Grant date | May 24, 2011 |
| Priority date | — |
| Expiry date | Sep 17, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Provided is a method for determining one or more profile parameters of a structure using an optical metrology model, the optical metrology model including a profile model, an approximation diffraction model, and a fine diffraction model. A simulated approximation diffraction signal is generated based on an approximation diffraction model of the structure. A set of difference diffraction signals is obtained by subtracting the simulated approximation diffraction signal from each of simulated fine diffraction signals and paired with the corresponding profile parameters. A machine learning system is trained using the pairs of difference diffraction signal and corresponding profile parameters. A measured diffraction signal adjusted by the simulated approximation diffraction signal is input into the trained machine learning system and generates the corresponding profile parameters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.