Patent ID: 6682964
Filing Date: 2004-01-27
Classification: H01L

Abstract:
A method of fabricating TFT for a liquid crystal display device, comprising:forming a buffer layer on a substrate; forming an amorphous semiconductor layer on the whole buffer layer; patterning the amorphous semiconductor layer to have an island shape, the island-shaded amorphous semiconductor layer having a channel region and source and drain ohmic contact regions each positioned at opposing ends of the channel region; forming a protecting layer on the entire surface of the island-shaped amorphous semiconductor layer; doping n+(or p+) ions on the source and drain ohmic contact regions of the island-shaded amorphous semiconductor layer while covering the channel region with a photoresist; irradiating laser beams on the amorphous semiconductor layer having the island-shape, thereby simultaneously crystallizing and activating the island-shaped amorphous semiconductor layer so as to have a polycrystalline structure; forming a first insulating layer on the substrate to cover the polycrystalline semiconductor layer; forming a gate electrode on the first insulating layer and over the channel region; forming a second insulating layer on the first insulating layer so as to cover the gate electrode; forming source and drain contact holes penetrating both the first and second insulating layers, the source and drain contact holes exposing the source and drain ohmic contact regions of the polycrystalline semiconductor layer, respectively; and forming the source and drain electrodes on the second insulating layer, the source and drain electrodes having electrical connection to the source and drain ohmic contact regions of the polycrystalline semiconductor layer, respectively.