Methods and apparatus for calculating substrate model parameters and controlling lithographic processing
US11300891B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 2020 |
| Grant date | Apr 12, 2022 |
| Priority date | — |
| Expiry date | Dec 3, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7046
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Offline metrology measurements are performed on substrates that have been subjected to lithographic processing. Model parameters are calculated by fitting the measurements to an extended high-order substrate model defined using a combination of basis functions that include an edge basis function related to a substrate edge. A radial edge basis function may be expressed in terms of distance from a substrate edge. The edge basis function may, for example, be an exponential decay function or a rational function. Lithographic processing of a subsequent substrate is controlled using the calculated high-order substrate model parameters, in combination with low-order substrate model parameters obtained by fitting inline measurements to a low order model.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.