Patent ID: 7659989
Filing Date: 2010-02-09
Classification: B23K,H01L

Abstract:
1. A method of calibrating a focal plane of a mask imaging system for use with a sequential lateral solidification (SLS) system, the method comprising: utilizing the SLS system to form a two dimensional test pattern in a substrate by directing a mask image onto said substrate in a predetermined pattern; varying a z-position of the focal position of the SLS system while forming the test pattern, with the test pattern exhibiting variations in surface texture in different regions at different z-positions; storing information concerning the variation of the focal position in a data processing system; directing an inspection beam of light onto the different regions of the test pattern at a predetermined angle; detecting the specular and scattered reflections of the inspection beam with an optical detector; analyzing the variations in the specular and scattered reflections as a function of the different regions of the test pattern; and comparing the analysis of the reflections with the stored information to select one of the z-positions as a calibration.