Method for fabricating tft substrate for lcd

PURPOSE: A method for fabricating a TFT(Thin Film Transistor) substrate of an LCD(Liquid Crystal Display) is provided to delay the exposure of data lines to the etching gas via contact holes, thereby preventing the short or corrosion of the data lines. CONSTITUTION: A method for fabricating a TFT substrate of an LCD includes the steps of forming gate wires having gate lines(22), gate electrodes(26) connected to the gate lines and gate pads(24) on an insulating substrate(10) by stacking and patterning a conductive material, forming a gate insulating film, forming a semiconductor layer(40) on the gate insulating film, forming data wires having data lines(62) intersecting the gate lines, source electrodes(65) connected to the data lines and adjacent to the gate electrodes, drain electrodes(66) opposing the source electrodes with respect to the gate electrodes, and data pads(68) connected to the data lines by stacking and patterning a conductive material, forming first to third contact holes(72,74,76) by stacking and patterning a protection film to expose the gate pads, the data pads and the drain electrodes, and forming pixel electrodes(82) electrically connected to the drain electrodes via the third contact holes, wherein the contact holes are formed by photo-etching using a photosensitive film pattern having different thickness partially.