Voltage contrast method for semiconductor inspection using low voltage particle beam
US6344750B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 1999 |
| Grant date | Feb 5, 2002 |
| Priority date | — |
| Expiry date | Jan 8, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/849
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Defects in a patterned substrate are detected by inspection with a charged particle beam inspection tool which generates an image of a portion of the patterned substrate and compares the image with a reference in order to identify any defects in the patterned substrate. Parameters of the tool are optimized to improve image uniformity and contrast, particularly voltage contrast. Prior to imaging an area of the substrate, the tool charges an area surrounding the image area to eliminate or reduce the effects caused by asymmetrical charging in the surrounding area. The tool alternates between charging the surrounding area and imaging the image area to produce a plurality of images of the image area, which are then averaged. The result is a highly uniform image with improved contrast for accurate defect detection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.