Method and apparatus for correcting rotational errors during inspection of reticles and masks
US4737920A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 28, 1984 |
| Grant date | Apr 12, 1988 |
| Priority date | — |
| Expiry date | Nov 28, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70616
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and apparatus for inspecting masks and reticles by simplifying rotational alignment thereof so as to shorten alignment time is proposed wherein a rotational angle representing a rotational error between a reference substrate and a substrate to be inspected is measured in advance, the substrate to be inspected being provided with the same circuit patterns as those of the reference substrate in one-to-one correspondence, a position of a stage having these substrates thereon is automatically measured, and a measurement error caused by the rotational error can be automatically corrected, thereby providing accurate measured values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.