METHOD FOR MANUFACTURING THIN FILM TRANSISTOR FOR LIQUID CRYSTAL DISPLAY HAVING INTEGRATED TYPE DRIVING CIRCUIT

摘要

PURPOSE: A method for manufacturing a TFT(Thin Film Transistor) for an LCD(Liquid Crystal Display) having an integrated type driving circuit is provided to control easily the length of LDD(Lightly Doped Drain) through the control of a PR(Photo Resist) ashing process. CONSTITUTION: A buffer layer(112) is formed on an insulation substrate(110). An activation layer(114) made of polysilicon material is patterned on an upper portion of the buffer layer(112). A gate insulation film(116) is formed on the activation layer(114). The first PR(Photo Resist) pattern(120) is formed on an upper portion of the gate insulation film(116) by a photolithography process. By using the first PR pattern(120) as a mask, a gate pattern(118) corresponding to the first PR pattern(120) is formed by an exposed gate material. Both edge portions of the activation layer(114) are doped by n+ impurity ions by using the first PR pattern(120) as a mask. The second PR pattern(122) is formed by performing an ashing process of the first PR pattern(120) so that both sides of the gate pattern(118) is exposed with a constant length. By using the second PR pattern(122) as a mask, the exposed gate pattern(118) is exposed, so that the gate electrode having a pattern structure corresponding to the second PR pattern(122) is completed.