Inspection method and apparatus, lithographic system and device manufacturing method
US10132763B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 2013 |
| Grant date | Nov 20, 2018 |
| Priority date | — |
| Expiry date | Jun 18, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An inspection method determines values of profile parameters of substrate patterns. A baseline substrate with a baseline pattern target (BP) is produced that has a profile described by profile parameters, for example CD (median critical dimension), SWA (side wall angle) and RH (resist height). Scatterometry is used to obtain first and second signals from first and second targets. Values of differential pattern profile parameters are calculated using a Bayesian differential cost function based on a difference between the baseline pupil and the perturbed pupil and dependence of the pupil on pattern profile parameters. For example, the difference is measured between a baseline process and a perturbed process for stability control of a lithographic process. Fed-forward differential stack parameters are also calculated from observations of stack targets on the same substrates as the pattern targets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.