Determining defect depth and contour information in wafer structures using multiple SEM images
US6353222B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 3, 1998 |
| Grant date | Mar 5, 2002 |
| Priority date | — |
| Expiry date | Sep 3, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2817
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A SEM review station provides a plurality of images of a defect area of a wafer structure, particularly a semiconductor integrated circuit, during manufacture. Inspection of the multiple images provides a depth determination and/or contour information. Knowing the depth of a defect is useful for determining a corresponding manufacturing step and chamber in which a defect was introduced. One SEM review station provides a stereoscopic SEM image signal by combining signals from two images taken from different perspectives, and determines the depth of a defect. Another SEM review station provides contour information through three images taken with varying directions of electron detection so is that shading differences can be used to characterize the defect as flat, as a protrusion, or as a recess.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.