Mask design utilizing dummy features
US6258489A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1999 |
| Grant date | Jul 10, 2001 |
| Priority date | — |
| Expiry date | Jul 9, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photolithography mask includes dummy features adjacent to features to be printed (printable features). The dummy features are smaller than the resolution (which is approximately equal to the critical dimension) of the photolithography system so that the resist is not fully developed in the areas of the dummy features. Thus, the dummy features will not be etched into the surface below. However, the proximity effects caused by the dummy features will act to suppress sidelobes and/or increase the depth of focus. Dummy features may be provided adjacent to both isolated and densely-packed printable features, thereby equalizing the proximity effects acting on both types features so that isolated printable features will print approximately the same as densely-packed printable features and the printability of both isolated and closely-packed features will be enhanced. The size and shape of the dummy features may be adjusted for the particular application.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.