Model-based assist feature placement using inverse imaging approach
US8010913B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 2009 |
| Grant date | Aug 30, 2011 |
| Priority date | — |
| Expiry date | Feb 25, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F30/398
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Some embodiments provide techniques and systems to identify locations in a target mask layout for placing assist features. During operation, an embodiment can determine a spatial sampling frequency to sample the target mask layout, wherein sampling the target mask layout at the spatial sampling frequency prevents spatial aliasing in a gradient of a cost function which is used for computing an inverse mask field. Next, the system can generate a grayscale image by sampling the target mask layout at the spatial sampling frequency. The system can then compute the inverse mask field by iteratively modifying the grayscale image. The system can use the gradient of the cost function to guide the iterative modification process. Next, the system can filter the inverse mask field using a morphological operator, and use the filtered inverse mask field to identify assist feature locations in the target mask layout.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.