Method and apparatus for detecting aberrations in a projection lens utilized for projection optics
US6753954B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 6, 2000 |
| Grant date | Jun 22, 2004 |
| Priority date | — |
| Expiry date | Mar 9, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/706
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of detecting aberrations associated with a projection lens utilized in an optical lithography system. The method includes the steps of forming a mask for transferring a lithographic pattern onto a substrate, forming a plurality of non-resolvable features disposed on the mask, where the plurality of non-resolvable features are arranged so as to form a predetermined pattern on the substrate, exposing the mask using an optical exposure tool so as to print the mask on the substrate, and analyzing the position of the predetermined pattern formed on the substrate and the position of the plurality of non-resolvable features disposed on the mask so as to determine if there is an aberration. If the position of the predetermined pattern formed on the substrate differs from an expected position, which is determined from the position of the plurality of non-resolvable features, this shift from the expected position indicates the presence of an aberration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.