Mask and method for focus monitoring
US6440616B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 2000 |
| Grant date | Aug 27, 2002 |
| Priority date | — |
| Expiry date | Nov 9, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/26
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
There is disclosed a focus-monitoring mask which is adapted to be employed on an occasion of transferring a pattern on a wafer by way of photolithography, the mask comprising a first pattern region having at least one first monitor pattern which is constituted by a first opening surrounded by a first film or constituted by the first film surrounded by the first opening, and a second pattern region having at least one second monitor pattern which is constituted by a second opening surrounded by a second film or constituted by the second film surrounded by the second opening, and is capable of giving a predetermined phase difference to an exposure light passing through the second film relative to an exposure light passing through the second opening, wherein the first and second monitor patterns have a configuration in which both ends thereof are tapered from a central portion thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.