Thin film transistor manufacturing method and substrate structure

Abstract

A method of TFT (Thin Film Transistor) manufacturing and a substrate structure are provided. The structure includes a substrate and a self-alignment mask. A self-alignment mask on a substrate is first manufactured and then the self-alignment mask may synchronously extend with the substrate during the thermal process. When an exposure light source is provided on the side without a TFT formed, the self-alignment mask can overcome the problem that when a plastic substrate extends, the positions of the source and drain to be formed on the plastic substrate are incorrect, which has a great effect on the accuracy of alignment. As the result, the positions of the source and drain can be defined accurately.

1 . A method for manufacturing a thin film transistor comprising the steps of:
 providing a substrate, the substrate having a first surface and a second surface wherein the first surface is used for forming a thin film transistor thereon, the thin film transistor including a source, a drain, and a gate;   forming an opaque thin film on the second surface; processing the opaque thin film to form a mask;   forming a gate on the first surface;   forming a transparent insulation layer on the gate and the first surface;   forming a transparent electrode layer on the transparent insulation layer;   forming a photo resist on the transparent electrode layer;   providing an exposure light source at a side of the second surface, the exposure light source defining positions of a source and a drain on the transparent electrode layer with the first mask and forming the source and the drain by processing the transparent electrode layer; and   forming an active layer, disposed between the source and the drain and electrically connecting them.   
     
     
         2 . The method as claimed in  claim 1  wherein the thin film transistor is an organic thin film transistor. 
     
     
         3 . The method as claimed in  claim 1  wherein the first mask has a position, a measure of area, and a shape complementary to the source and the drain. 
     
     
         4 . The method as claimed in  claim 1  wherein the transparent insulation layer is made by a printing process or an inorganic deposition process. 
     
     
         5 . The method as claimed in  claim 1  wherein the active layer is made of an organic or inorganic material. 
     
     
         6 . The method as claimed in  claim 1  wherein the active layer, the source, and the drain are further covered by a passivation layer. 
     
     
         7 . The method as claimed in  claim 6  wherein the passivation layer is made by a spin coating process or a printing process. 
     
     
         8 . A method for manufacturing a thin film transistor comprising the steps of:
 providing a substrate, the substrate having a first surface and a second surface wherein the first surface is used for forming a thin film transistor thereon, the thin film transistor including a source, a drain, and an opaque gate;   forming an opaque gate on the first surface;   forming a transparent insulation layer on the opaque gate and the first surface;   forming a transparent electrode layer on the transparent insulation layer;   forming a negative type photo resist layer on the transparent electrode layer;   providing an exposure light source at a side of the second surface, the exposure light source defining a channel width of the thin film transistor with the opaque gate;   processing the transparent electrode layer to form a source and a drain; and   forming an active layer, disposed between the source and the drain and electrically connecting them.   
     
     
         9 . The method as claimed in  claim 8  wherein the thin film transistor is an organic thin film transistor. 
     
     
         10 . The method as claimed in  claim 8  wherein the transparent insulation layer is made by a printing process or an inorganic deposition process. 
     
     
         11 . The method as claimed in  claim 8  wherein the active layer, the source, and the drain are further covered by a passivation layer. 
     
     
         12 . The method as claimed in  claim 11  wherein the passivation layer is made by a spin