Manufacture method of TFT substrate involving reduced number of masks and structure of TFT substrate so manufactured

A manufacture method of a thin-film transistor (TFT) substrate, comprising steps of:

• step 1, providing a substrate and deposing and patterning a first metal layer on the substrate through a photolithographic process to form a gate;
• step 2, deposing a gate isolation layer on the gate and the substrate;
• step 3, sequentially deposing an oxide semiconductor layer and a first photoresist layer on the gate isolation layer such that the first photoresist layer is directly located on the oxide semiconductor layer;
• step 4, employing the gate as a mask to implement a back side exposure operation to the first photoresist layer to form an island shaped first photoresist layer directly over the gate;
• step 5, conducting a process of solely etching the oxide semiconductor layer according to a pattern of the island shaped first photoresist layer to form an island shaped oxide semiconductor layer directly over the gate, and removing the island shaped first photoresist layer that is used in the process of solely etching the oxide semiconductor to form the island shaped oxide semiconductor layer;
• step 6, deposing and patterning an etching stopper layer on the island shaped oxide semiconductor layer, which is formed with the island shaped first photoresist layer, and the gate isolation layer to form an island shaped etching stopper layer on the oxide semiconductor layer;
• wherein a width of the island shaped etching stopper layer is smaller than a width of the island shaped oxide semiconductor layer;
• and the island shaped etching stopper layer covers a central part of the island shaped oxide semiconductor layer and exposes two side parts of the island shaped oxide semiconductor layer;
• step 7, deposing and patterning a second metal layer on the island shaped etching stopper layer and the gate isolation layer to form a source/a drain;
• wherein the source/the drain contact the two side parts of the island shaped oxide semiconductor layer to establish electrical connections;
• step 8, sequentially deposing a protecting layer and a second photoresist layer on the source/the drain and the island shaped etching stopper layer, and implementing gray scale exposure and development to the second photoresist layer to correspondingly form a full exposure region in a position of forming a pixel electrode via and form a gray scale exposure region in a position of forming a pixel electrode;
• step 9, removing the protecting layer under the full exposure region to form the pixel electrode via, and implementing an ashing process to the second photoresist layer to remove the gray scale exposure region;
• step 10, deposing a pixel electrode layer on the remaining second photoresist layer and the protecting layer;
• step 11, removing the remaining second photoresist layer and a part of the pixel electrode layer deposed thereon to form a pixel electrode;
• wherein the pixel electrode fills the pixel electrode via and contacts the source/the drain to establish electrical connections;
• and
• step 12, implementing an annealing process to the substrate.