Methodology and system for determining numerical errors in pixel-based imaging simulation in designing lithographic masks
US7975244B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 2008 |
| Grant date | Jul 5, 2011 |
| Priority date | — |
| Expiry date | Jan 24, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/68
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method is provided for designing a mask that includes the use of a pixel-based simulation of a lithographic process model, in which test structures are designed for determining numerical and discretization errors associated with the pixel grid as opposed to other model inaccuracies. The test structure has a plurality of rows of the same sequence of features, but each row is offset from other rows along an x-direction by a multiple of a minimum step size, such as used in modifying masks during optical proximity correction. The images for each row are simulated with a lithographic model that uses the selected pixel-grid size and the differences between row images are compared. If the differences between rows exceed or violate a predetermined criterion, the pixel grid size may be modified to minimize discretization and/or numerical errors due to the choice of pixel grid size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.