Systems and methods for a wafer inspection system using multiple angles and multiple wavelength illumination
US6956644B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2001 |
| Grant date | Oct 18, 2005 |
| Priority date | — |
| Expiry date | Jan 15, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for detecting an anomaly on a top surface of a substrate comprises directing a first radiation beam having a first wavelength at the top surface of the substrate at a first angle measured from normal, and directing a second radiation beam having a second wavelength at the top surface of the substrate at a second angle measured from normal, wherein the second wavelength is not equal to the first wavelength. The method then comprises detecting scattered radiation from the first radiation beam and the second radiation beam to detect the presence of particles or COPs, and to differentiate between the two. Differences in the scattered radiation detected from the first radiation beam and from the second radiation beam provide the data needed to differentiate between particles and COPs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.