Method and apparatus for identifying misregistration in a complimentary phase shift mask process
US6774998B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 2001 |
| Grant date | Aug 10, 2004 |
| Priority date | — |
| Expiry date | Sep 18, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70633
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method includes providing a wafer having a first grating structure and a second grating structure formed in a photoresist layer. At least a portion of the first and second grating structures is illuminated with a light source. Light reflected from the illuminated portion of the first and second grating structures is measured to generate a reflection profile. Misregistration between the first and second grating structures is determined based on the reflection profile. A processing line includes a photolithography stepper, a metrology tool, and a controller. The photolithography stepper is adapted to process wafers in accordance with an operating recipe. The metrology tool is adapted to receive a wafer processed in the stepper. The wafer has a first grating structure and a second grating structure formed in a photoresist layer. The metrology tool includes a light source, a detector, and a data processing unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.