Focus determination for laser-mask imaging systems
US7659989B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 2007 |
| Grant date | Feb 9, 2010 |
| Priority date | — |
| Expiry date | Aug 5, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02686
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A system and method for calibrating the focal position of the imaging plane of a sequential lateral solidification (SLS) system. A test pattern is formed on a test substrate while varying the z-position of the focal position. Information concerning the z-position of the focal position is stored by a data processing system for various positions in the test pattern. An inspection light beam is directed onto the test pattern at a predetermined angle. The reflection of the inspection light beam is detected by an optical detector. The data processing system analyzes the reflection and determines whether the reflected light is substantially specular or substantially scattered. The data processing system uses the analysis of the reflected light and the information concerning the z-position of the focal position to select an optimal focal position for calibrating the SLS system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.