Back-channel-etched tft substrate and manufacturing method thereof

Abstract

The invention provides a BCE TFT substrate and manufacturing method thereof. The method comprises forming a first IGZO thin film with polycrystalline IGZO particles in a predetermined area of active layer before sputtering IGZO, the polycrystalline IGZO particles in the first IGZO thin film used as seed crystal during sputtering to grow a C-axis crystallized IGZO in good crystalline state to form a second IGZO thin film. The first and second IGZO thin films form an active layer. Because the surface of the active layer is presented as C-axis crystallized IGZO, the active layer is not damaged by the copper etchant during etching source and drain so as to ensure stable performance of active layer and to avoid the development of special copper etching solution. As such, the BCE TFT substrate has stable electrical performance. The BCE TFT substrate manufactured by the above manufacturing method has stable electrical performance.

What is claimed is: 
     
         1 . A back-channel-etched (BCE) thin film transistor (TFT) substrate, comprising: a base substrate, a gate disposed on the base substrate, a gate insulating layer disposed on the base substrate and the gate, an active layer disposed on the gate insulating layer and corresponding to the above of the gate, a source and a drain separated with interval and disposed on the active layer and the gate insulating layer, a passivation layer disposed on the source, the drain, and the active layer, and a pixel electrode disposed on the passivation layer;
 a via being disposed on the passivation layer and corresponding to the above of the drain, the pixel electrode contacting with the drain through the via;   the active layer comprising the first IGZO thin film on the gate insulating layer and the second IGZO thin film on the first IGZO thin film; the first IGZO thin film being presented as a thin film formed by polycrystalline IGZO particles; the second IGZO thin film being presented as a C-axis crystallized IGZO thin film.   
     
     
         2 . The BCE TFT substrate as claimed in  claim 1 , wherein the material of the gate, the source and the drain is copper; the material of the pixel electrode is indium tin oxide (ITO).