Use of fiducial marks for improved blank wafer defect review
US5847821A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1997 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Jul 10, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB82Y15/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for navigating directly to defects on a blank wafer caused by particles dropped from process tools. A blank wafer is marked with fiducial marks, the number of initial defects on the blank wafer is determined and the position coordinates of the initial defects and the fiducial marks are recorded. The blank wafer is placed into a selected process tool and the additional defects that are caused by particles dropped from the process tool are detected in an inspection tool and their position coordinates are determined and recorded as well as the position coordinates of the fiducial marks. The blank wafer is then placed in an analysis tool that is able to navigate directly to each of the additional defects at a high magnification using the position coordinates of the fiducial marks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.