METHOD FOR FABRICATING THIN FILM TRANSISTOR SUBSTRATE

摘要

PURPOSE: A method for fabricating a thin film transistor substrate is provided to form a lightly doped region with a desired width. CONSTITUTION: A polysilicon layer(150) is formed on an insulating substrate(110), and a gate insulating layer(140) is formed on the polysilicon layer. A metal layer is formed on the gate insulating layer and patterned to form a gate line including a gate electrode(123). Conductive impurities are heavily doped into the polysilicon layer to form source and drain regions(153,155) and an undoped channel region(154). A lightly doped region(152) is formed in the polysilicon layer. The first interlevel insulating layer(601) having the first and second contact holes(141,142) are formed to cover the gate line. A data line including a source electrode(173) connected to the source region through the first contact hole is formed on the first interlevel insulating layer, and a drain electrode(175) connected to the drain region through the second contact hole is formed on the first interlevel insulating layer. The second interlevel insulating layer(602) having the third contact hole(143) is formed to cover the data line and drain electrode. A pixel electrode(190) connected to the drain electrode through the third contact hole is formed on the second interlevel insulating layer.