Method for detecting phase error of a phase shift mask
US5817437A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 1996 |
| Grant date | Oct 6, 1998 |
| Priority date | — |
| Expiry date | Oct 3, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/84
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for detecting the phase error of a phase shift mask simply and with ease is disclosed and comprises the steps of: arranging a plurality of phase shift patterns, each having a predetermined width and serving to shift the light transmitted through predetermined regions of a transparent substrate of the phase shift mask, at a regular space on the transparent substrate; arranging a pattern for detecting phase error in which a light screen with a predetermined width is located between the predetermined regions of the transparent substrate and the phase shift mask; patterning a wafer by use of the phase shift mask and the patterns for detecting phase error; comparing the sizes by defocuses of the patterns in which phase is shifted with those of the patterns in which phase is not shifted; and utilizing the difference in the pattern size to detect the phase error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.