Extraction of imaging parameters for computational lithography using a data weighting algorithm
US8806388B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 2013 |
| Grant date | Aug 12, 2014 |
| Priority date | — |
| Expiry date | Mar 22, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of computational lithography includes collecting a critical dimension (CD) data set including CD data from printing a test structure including a set of gratings which provide a plurality of feature types including different ratios of line width to space width, where the printing includes a range of different focus values. The CD data is weighted to form a weighted CD data set using a weighting algorithm (WA) that assigns cost weights to the CD data based its feature type and its magnitude of CD variation with respect to a CD value for its feature type at a nominal focus (nominal CD). The WA algorithm reduces a value of the cost weight as the magnitude of variation increases. At least one imaging parameter is extracted from the weighted CD data set. A computational lithography model is automatically calibrated using the imaging parameter(s).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.