Focusing and leveling measurement device and method
US10656507B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2017 |
| Grant date | May 19, 2020 |
| Priority date | — |
| Expiry date | May 22, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/00
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A measurement device and method for focusing and leveling are disclosed. The device includes a measuring optical path and a first monitoring optical path. Measuring light in the measuring optical path interacts with a wafer and is then incident on a measuring detector to form thereon a measuring mark. First monitoring light in the first monitoring optical path is incident on a measuring detector to form thereon a first monitoring mark. An error in a measurement result of the wafer that arises from a drift of the measuring detector can be eliminated by compensating for a vertical deviation of the wafer obtained by subtracting a drift of the first monitoring mark from a displacement of the measuring mark. In this way, measurement accuracy and stability can be improved by monitoring and correcting the drift of the measuring detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.