System and method for aligning pattern areas on opposing substrate surfaces
US6222198A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 1998 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | Nov 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7003
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system and method for achieving alignment of a mask and substrate focuses a first image (e.g., a reticle) on a first position of a first substrate surface, and determines whether the first position is aligned with a second position on an opposing second substrate surface based on a second image formed based on light from a micro-optical device located on the second surface which collects light from a first image focused thereon. To determine whether the first and second positions are aligned, the first image and the second image are projected on an image plane and compared, the first and second positions being aligned when the first image and the second image are coincident on the image plane. A mask and/or alignment pattern may be formed on the opposing substrate surfaces, and used to generate aligned optics on those surfaces. As such, precise alignment between optics on opposing surfaces of a substrate can be achieved. In this system, the secondary image may or may not be an exact replica of the first reticle image, depending upon the type of micro-optical device used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.