TFT-LCD array substrate and manufacturing method thereof

A manufacturing method for a thin film transistor liquid crystal display (TFT-LCD) array substrate, the array substrate including a gate electrode region, a data line region, a semiconductor region, a source electrode region, a drain electrode region, a gate line region and a pixel electrode region, wherein the manufacturing method comprises:

• Step 1, depositing a transparent conductive film, a source/drain metal film and a doped semiconductor film on a transparent substrate sequentially, forming patterns of a doped semiconductor layer, a source electrode and a drain electrode of a thin film transistor, a data line and a pixel electrode by a first patterning process, wherein the doped semiconductor layer remains on the source electrode and the drain electrode;
• Step 2, depositing a semiconductor film on the whole transparent substrate after Step 1, forming a pattern of a semiconductor layer that includes a channel of the thin film transistor by a second patterning process;
• and
• Step 3, depositing an insulating film and a gate metal film on the whole transparent substrate after Step 2, forming patterns of a gate line and a gate electrode of the thin film transistor by a third patterning process, wherein the gate electrode is located above the channel of the thin film transistor,
• wherein step 1 comprises:
• after depositing the transparent conductive film, the source/drain metal film and the doped semiconductor film on the transparent substrate sequentially, applying a first photoresist layer on the doped semiconductor film;
• exposing the first photoresist layer with a dual tone mask and developing the exposed first photoresist layer so that the first photoresist layer in the data line region, the source electrode region and the drain electrode region has a first thickness, the first photoresist layer in the pixel electrode region has a second thickness which is smaller than the first thickness, and the first photoresist layer does not remain in remaining regions;
• removing the doped semiconductor film, the source/drain metal film and the transparent conductive film in the remaining regions by a first etching process;
• removing the first photoresist layer with the second thickness by an ashing process so as to expose the doped semiconductor layer in the pixel electrode region;
• removing the doped semiconductor film, the source/drain metal film in the pixel region by a second etching process;
• and
• removing the remaining first photoresist layer.