System and method of optically inspecting surface structures on an object
US6292260A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1999 |
| Grant date | Sep 18, 2001 |
| Priority date | — |
| Expiry date | Jun 23, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method of optically inspecting structures on the surface of an object, such as a semiconductor wafer. A platform is used to support the object under examination, and provided thereat are lights or other energy sources for illumination disposed at a selected angular orientation. Optimum illumination is achieved by orienting two opposing lateral energy sources to direct energy along the surface of the object at a very low angle, and using them in conjunction with a coaxial light source that emits energy, which is directed downward toward the surface. Energy reflected back from the surface is captured as an image by a suitable device such as a CCD camera. The lighting may be controlled by an attached computer, which can also be used to process and store the captured image and analyze it to detect and catagorize defects in the object being inspected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.