OPTICAL SYSTEM FOR ANNEALING POLY-SILICON THIN FILM BY LASER

摘要

PROBLEM TO BE SOLVED: To provide a gas discharge laser crystallization apparatus for performing transformation of crystal growth or orientation in a film on a workpiece.SOLUTION: A laser system is configured as a POPA laser system and further comprises: a relay optical system operative to direct a first output laser light pulse beam from a first laser PO unit into a second laser PA unit; and a timing and control module adjusting timing of occurrence of gas discharge in the first and second laser units within plus or minus 3 nsec, to produce the second laser output light pulse beam as amplification of the first laser output light pulse beam. The system comprises a divergence control part in an oscillator laser unit. The divergence control part comprises an unstable oscillation control part. The system further comprises a beam pointing control mechanism and a beam position control mechanism, between the laser and the workpiece.SELECTED DRAWING: Figure 6