Semiconductor wafer defect monitoring
US5392113A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1992 |
| Grant date | Feb 21, 1995 |
| Priority date | — |
| Expiry date | Sep 30, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method and apparatus for detecting the presence of selected types of defects, such as chemical stains from a liquid photoresist material or a liquid dielectric material, on a non-visible chosen surface of a semiconductor water that has undergone at least one processing step. In one embodiment, a support substrate for, the wafer is provided that has a highly reflecting surface adjacent to the chosen surface. The reflecting surface and the chosen surface are moved apart, and the chosen surface is illuminated with light to form an optical image of the chosen surface. The optical image of the chosen surface is reflected in the reflecting surface, and the reflected optical image is examined for the presence of selected types of defects. In another embodiment, a portion of this reflecting surface is initially contiguous to the chosen surface. A selected defect, if any, on the chosen surface changes a surface characteristic of the reflecting surface so that the presence of this defect on the chosen surface is visually perceptible on the reflecting surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.