Process for pattern searching and a device for positioning of a mask to a workpiece
US6072915A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 13, 1997 |
| Grant date | Jun 6, 2000 |
| Priority date | — |
| Expiry date | Jan 13, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/00
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A process for pattern searching in which position coordinates of patterns on a workpiece with a rough surface can be determined automatically and with high precision, and a device for executing the process are achieved by CCD cameras and the like picking up patterns which are located on a workpiece with a rough surface, and which are formed only by intersecting lines, and by a storage means storing light-dark signals. Furthermore, according to the invention, the image signals are integrated in directions which are each parallel to the lines of the patterns, by which integral signals .SIGMA.Xn, .SIGMA.Yn are determined. By integrating the image signals, the images which are formed as a result of surface roughness are averaged. The integration signals clearly yield boundary positions of the patterns, and by differentiating these integral signals, the pattern positions are determined based on their peak positions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.