Method of reducing critical dimension bias of dense pattern and isolation pattern
US7097945B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 2003 |
| Grant date | Aug 29, 2006 |
| Priority date | — |
| Expiry date | Nov 15, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/70
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of reducing a critical dimension (“CD”) bias between a dense pattern and an isolation pattern is disclosed. The method includes a first step of providing a mask having a dense pattern, an isolation pattern and the other area of the mask is transparent, in which mask the dense pattern has a first opaque pattern and the isolation pattern has a second opaque pattern. The second step of the method is forming a virtual pattern around the isolation pattern, in which a distance between the virtual pattern and the isolation pattern is y, and the virtual pattern has a pattern line width x. By forming the virtual pattern around the isolation pattern, the flare effect of the isolation pattern is close to that of the dense pattern, thus the CD bias between a dense pattern, and an isolation pattern is reduced, and the process window does not shrink.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.