Focus monitor structure and method for lithography process
US6063531A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1998 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Oct 6, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70641
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focus monitor structure is placed on a reticle or mask near the production device structures, such as integrated circuits, to monitor the focal conditions of the lithography process as well as other parameters, such as the critical dimension, and proximity effects. The focus monitor structure includes a series of densely packed parallel lines and an isolated line along with a line that is positioned orthogonally to the densely packed lines forming an "L" shaped structure. The focus monitor structure also includes a plurality of rectangular islands that create post structures when patterned in the resist layer. The lines of the focus monitor structure are approximately the critical dimension and the rectangular islands vary in width between .+-.10% of the critical dimension. By manually or automatically inspecting the focus monitor structure after it is patterned into a layer of resist, including measuring the width of the resist lines and the resist profile angle of the orthogonal line, information relating to the critical dimension as well as the focal conditions of the lithography process can be determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.