| 摘要 |
A laser scanning system suitable for annealing applications is described. The problem of keeping the window (through which the laser shines into the system) clean, even though the laser ejects a considerable amount of debris, has been solved by inserting a moveable shutter close to the window between it and the substrate. The center portion of the shutter is an insert of optical quality quartz that is just large enough to allow the laser beam to pass through unimpeded and undiverted. By moving the beam and the shutter in concert it is ensured that the beam always passes through the insert. Most of the debris ejected by the laser as a side effect of its operation is trapped on the shutter. Relatively little material ends up on the quartz insert but when sufficient has accumulated there, the insert can be replaced at much lower cost than replacing the window. By moving the beam back and forth together with movement of the substrate, the entire area of the film on the substrate may be scanned by the beam. In a second embodiment, the quartz insert is omitted and an open slit left in its place. With this arrangement debris will eventually accumulate on the window but at a greatly reduced rate relative to an unprotected window.
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