Alignment system wafer stack beam analyzer
US10488767B2 · kind B2 · utility
1Cited by
6References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 17, 2017 |
| Grant date | Nov 26, 2019 |
| Priority date | — |
| Expiry date | May 17, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7088
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An alignment system obtains the characteristics of the light coming back from a wafer stack. A beam analyzer measures changes in wavelength, polarization, and beam profile. This measured information allows for in-line process variation corrections. The correction provides optical monitoring of individual mark stack variations, and in turn provides information to reduce individual mark process variation-induced accuracy error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.