Methods for designing grating structures for use in situ scatterometry to detect photoresist defects
US7427457B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 2004 |
| Grant date | Sep 23, 2008 |
| Priority date | — |
| Expiry date | Nov 12, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/7065
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention discloses a system and method for designing grating structures for use in situ scatterometry during the photolithography process to detect a photoresist defect (e.g., photoresist erosion, pattern collapse or pattern bending). In one embodiment, a grating structure may be designed with a pitch or critical dimensional smaller than the one used for the semiconductor device. The pitch and the critical dimension of the grating structure may be varied. In another embodiment, the present invention provides for a feedback mechanism between the in situ scatterometry process and the photolithography process to provide an early warning of the existence of a photoresist defect. If a defect is detected on the wafer, the wafer may be sent to be re-worked or re-patterned, thereby avoiding scrapping the entire wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.