Large-particle monitoring with laser power control for defect inspection
US12345658B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 2021 |
| Grant date | Jul 1, 2025 |
| Priority date | — |
| Expiry date | Jul 8, 2042 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/8835
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A semiconductor wafer is inspected using a main laser beam and a secondary laser beam. The secondary laser beam leads the main laser beam and has lower power than the main laser beam. Using the secondary laser beam, a particle is detected on the semiconductor wafer having a size that satisfies a threshold. In response to detecting the particle, the power of the main laser beam and the power of the secondary laser beam are reduced. The particle passes through the main laser beam with the main laser beam at reduced power. After the particle has passed through the main laser beam with the main laser beam at the reduced power, the power of the main laser beam and the power of the secondary laser beam are restored in a controlled manner that is slower than a single step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.