Exposure for performing synchronized off-axis alignment
US6166392A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 1998 |
| Grant date | Dec 26, 2000 |
| Priority date | — |
| Expiry date | Nov 16, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70733
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An exposure has at least two wafer pads for holding wafers at the same time to perform different tasks including exposing a wafer, aligning a wafer, and loading or unloading a wafer synchronously. The exposure of the invention includes an exposing unit, a wafer supporting unit and a alignment beam scan unit. The wafer-supporting unit contains at least two wafer pads for holding wafers. The alignment beam scan unit contains an interferometer for detecting the interference patterns formed by the alignment beams and the alignment marks on the wafers. The tasks of aligning a wafer, and exposing a wafer, or loading/unloading a wafer can be performed on the wafers placed on each individual wafer pad synchronously.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.