Coaxial see-through inspection system
US12393125B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 2021 |
| Grant date | Aug 19, 2025 |
| Priority date | — |
| Expiry date | Aug 17, 2041 |
Classification
- Technology area (CPC —)General
Abstract
Aspects of the present disclosure provide an inspection system, which can include an image module and processing circuitry. The imaging module can image a wafer with a first light beam and a second light beam. The first light beam can be coaxially aligned with the second light beam, and image a first pattern located on a front side of a wafer to form a first image. The second light beam can image a second pattern located below the first pattern to form a second image via quantum tunneling imaging or infrared transmission imaging. The second light beam can have power sufficient to pass through at least a portion of a thickness of the wafer and reach the second pattern. The processing circuitry can perform image analysis on the first image and the second image to calculate an overlay value of the first and second patterns and/or defects of the wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.