Display device, method of production of the same, and projection type display device

Abstract

A display device able to raise a light resistance of pixel transistors without depending upon a light shielding structure and a method of production of same, wherein an average crystal grain size of a polycrystalline silicon filmforming an active layer of the pixel transistors is controlled to be relatively small so as to suppress a photo-leakage current. The smaller the crystal grain size, the larger the included crystal defects. Carriers excited by light irradiation are smoothly captured by a defect level, and an increase of a photo-leakage current is suppressed. On the other hand, the average crystal grain size of the polycrystalline silicon filmconstituting the peripheral transistors is controlled so as to become relatively large. The larger the crystal grain size, the larger the mobility of the carriers, and the higher the drivability of the peripheral transistors. This is because a higher speed operation is required for the peripheral transistors than the pixel transistors due to scanning of pixels and sampling of image signals.