PRODUCTION OF ACTIVE MATRIX SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To suppress the variation in the characteristics of active elements occurring in the stains of optical windows and to permit production in the state of maintaining a high display grade by arranging Si thin films on a substrate side in such a manner that the optical windows are stained as uniformly as possible. SOLUTION: The parts 20 of the substrate which are not used for display (not used for screens and driving circuits) are provided with dummy Si thin films 21. The dummy thin films 21 are formed by annealing amorphous Si by a plasma enhanced CVD and patterning the dehydrogenated thin films in a photoetching stage and are simultaneously formed with an Si thin film 5 for a thin film transistor. The amt. (area) of the dummy Si thin films 21 is so adjusted that the optical windows 7 are uniformly stained when the optical windows are irradiated with a linear laser beam. At this time, the Si is melted and crystallized by the irradiation with the laser in a vacuum and is changed to polycrystalline Si thin films. As a result, the optical windows are uniformly stained and, therefore, the variation in the characteristics of the active elements occurring in the stains of the optical windows is suppressed.