Feedback method utilizing lithographic exposure field dimensions to predict process tool overlay settings
US6735492B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 2002 |
| Grant date | May 11, 2004 |
| Priority date | — |
| Expiry date | Aug 31, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B13/026
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A system and method of monitoring and predicting tool overlay settings comprise generating current lot information, generating historical data, categorizing (binning) the historical data into discrete exposure field size ranges, and predicting current lot tool overlay settings based on the current lot information and historical data. The method monitors the overlay errors during each lot pass through each lithographic process operation. Moreover, the method uses a feedback sorting criteria to monitor the tool overlay settings. Furthermore, the current lot information comprises lithographic field dimensions, wherein the lithographic field optics distortion data is derived from the current lithographic process tool. Additionally, the historical data comprises same-bin lithographic field size dimensions of previous lots, which statistically means the data is derived from the same (or similar) bin of like lots, on the current lithographic process tool.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.