Multiple field of view calibration plate for use in semiconductor manufacturing
US5978081A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Jun 22, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An article of manufacture is provided both for coordinating multiple fields of view of a plurality of cameras so as to facilitate determining the distance between features on a semiconductor wafer, each feature being disposed within a different field of view, and for correcting image distortion within each field of view. The article of the invention includes a substantially rigid dimensionally-stable substrate, such as a plate, having a plurality of image distortion calibration targets, that are each located at a known relative position. In semiconductor wafer applications, each calibration target is disposed on the substrate so the target is in the field of view of a camera positioned to include a portion of the edge of the semiconductor wafer at run-time. In a preferred embodiment, each calibration target is disposed at an orientation angle such that a first principle axis of the calibration target is perpendicular to a tangent to the perimeter of the semiconductor wafer. In semiconductor wafer applications, it is preferred that a surface of the substrate be of a size and shape such that each calibration target disposed on the substrate can be in the field of view of a camera pos…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.