THIN FILM TRANSISTOR, THE FABRICATING METHOD OF THIN FILM TRANSISTOR, ORGANIC LIGHT EMITTING DISPLAY DEVICE AND THE FABRICATING METHOD OF ORGANIC LIGHT EMITTING DISPLAY DEVICE

摘要

A thin film transistor, a fabricating method thereof, an organic light emitting display device, and a fabricating method thereof are provided to crystallize amorphous silicon into polycrystalline silicon by directly radiating laser beams with narrow width and long length on the silicon without using a mask. A thin film transistor includes a substrate(300), a semiconductor layer(320), a gate electrode(328), a gate insulating film(330), and a source/drain electrode(352). The substrate has a buffer layer(310). The semiconductor layer is formed on the substrate and has a grain boundary in parallel with a crystal growth direction. A roughness of an upper surface of the semiconductor layer is less than 15nm. The gate electrode is formed corresponding to one region of the semiconductor layer. The gate insulating film insulates the semiconductor layer and the gate electrode from each other. The source/drain electrode is connected to the semiconductor layer.