Process for adjusting a photolithographic exposure machine and associated device
US5437948A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1993 |
| Grant date | Aug 1, 1995 |
| Priority date | — |
| Expiry date | Jul 12, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7026
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process and device for adjusting a photolithographic exposure machine, which is used for manufacturing integrated circuits. A guide wafer being furnished with identical test patterns, these test patterns are successively illuminated with white light beam and the coefficient of reflectivity of each test pattern is thus measured. For each location of the corresponding pattern, the law of correspondence of the coefficient of reflectivity as a function of the defocusing parameter for the illuminating beam is thus established. The optimum sharp focus value is determined by criterion of threshold of the value of the coefficient of reflectivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.