Method for fabricating thin film transistor array substrate and thin film transistor array substrate

A method for fabricating a thin film transistor array substrate including a plurality of pixels provided on a substrate;

• a plurality of thin film transistors corresponding to the plurality of pixels and each thin film transistor including a gate electrode, a source electrode, a drain electrode and a semiconductor layer having a channel portion;
• a source line connected to the source electrode;
• a pixel electrode connected to the drain electrode for applying a voltage through a liquid crystal layer including liquid crystal molecules;
• and a projection provided over the pixel electrode for controlling orientation of the liquid crystal molecules, comprising:
• a first step of forming a pattern comprising the gate electrode on the substrate by photolithography;
• a second step of forming a pattern comprising the thin film transistors including forming a multilayered body by stacking, on the substrate where the gate electrode has been formed, a gate insulating film, a semiconductor film to be made into the semiconductor layer and a conducting film including a transparent conducting film and covering the semiconductor film, and patterning the multilayered body by photolithography;
• and
• a third step including forming a protection layer covering the thin film transistors, forming the projection by patterning at least the protection layer, and forming the pixel electrode by exposing a part of the transparent conducting film by photolithography,
• the second step including a resist pattern forming procedure for forming a resist film covering the multilayered body, and forming, in the resist film, a first opening exposing the conducting film therein and disposed above a portion other than a region where the channel portion, the source line, the source electrode and the drain electrode are formed, and a second opening having a bottom portion with a given thickness and disposed above a portion of the multilayered body corresponding to the channel portion, so that when the first and second openings are formed in the resist film the first opening extends all the way through the resist film to expose the conducting film but the second opening does not extend all the way through the resist film;
• a first etching procedure for etching the conducting film exposed in the first opening and the semiconductor film disposed beneath the conducting film;
• and after the first etching procedure a second etching procedure for removing the bottom portion of the second opening to expose the conducting film and for etching the conducting film exposed therein.