Source and mask optimization by changing intensity and shape of the illumination source
US7864301B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 5, 2008 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Aug 5, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/705
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An illumination source is optimized by changing the intensity and shape of the illumination source to form an image in the image plane that maximizes the minimum ILS at user selected fragmentation points while forcing the intensity at the fragmentation points to be within a small intensity range. An optimum mask may be determined by changing the magnitude and phase of the diffraction orders to form an image in the image plane that maximizes the minimum ILS at user selected fragmentation points while forcing the intensity at the fragmentation points to be within a small intensity range. Primitive rectangles having a size set to a minimum feature size of a mask maker are assigned to the located minimum and maximum transmission areas ad centered at a desired location. The edges of the primitive rectangle are varied to match optimal diffraction orders O(m,n). The optimal CPL mask OCPL(x,y) is then formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.