Secondary target design for optical measurements
US9311431B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 2012 |
| Grant date | Apr 12, 2016 |
| Priority date | — |
| Expiry date | Sep 4, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG16Z99/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The disclosure is directed to improving optical metrology for a sample with complex structural attributes utilizing custom designed secondary targets. At least one parameter of a secondary target may be controlled to improve sensitivity for a selected parameter of a primary target and/or to reduce correlation of the selected parameter with other parameters of the primary target. Parameters for the primary and secondary target may be collected. The parameters may be incorporated into a scatterometry model. Simulations utilizing the scatterometry model may be conducted to determine a level of sensitivity or a level of correlation for the selected parameter of the primary target. The controlled parameter of the secondary target may be modified until a selected level of sensitivity or a selected level of correlation is achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.