Wafer alignment system
US6198535A · kind A · utility
4Cited by
4References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1998 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Nov 13, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7015
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wafer alignment system aligns a wafer by checking the alignment marks formed on the back surface of the wafer. A number of guiding rays are used to determine the corresponding alignment mark on the back of the wafer to ensure that the wafer is properly aligned. The alignment system of the invention also includes a wafer stage and a fixed base, wherein the wafer stage and the fixed base contains a number of apertures that allow the guiding rays to pass through and strike on the alignment marks on the wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.