TFT SUBSTRATE STRUCTURE AND MANUFACTURING METHOD THEREOF

摘要

The present invention provides a TFT substrate structure and a manufacturing method thereof. The TFT substrate structure of the present invention includes an N-type lightly-doped amorphous silicon layer and an N-type heavily-doped amorphous silicon layer arranged between an amorphous silicon layer and a metal layer to form a gradient of doping concentration so as to reduce the potential barrier between the metal layer and the amorphous silicon layer, making injection of electrons easy and reducing the leakage current without lowering an operation current, thereby improving the electrical property of the TFT. The manufacturing method of a TFT substrate structure of the present invention includes forming an N-type lightly-doped amorphous silicon layer and an N-type heavily-doped amorphous silicon layer between an amorphous silicon layer and a metal layer to effectively reduce the potential barrier between the metal layer and the amorphous silicon layer, making injection of electrons easy and reducing the leakage current without lowering an operation current, thereby improving the electrical property of the TFT.

主权项

1. A thin-film transistor (TFT) substrate structure, comprising a base plate, a gate terminal formed on the base plate, a gate insulation layer formed on the base plate and covering the gate terminal, an island-like semiconductor layer formed on the gate insulation layer to be located above and corresponding to the gate terminal, and a source terminal and a drain terminal formed on the gate insulation layer to respectively contact two side portions of the island-like semiconductor layer,
wherein the island-like semiconductor layer comprises, stacked from bottom to top, an amorphous silicon layer, an N-type lightly-doped amorphous silicon layer, and an N-type heavily-doped amorphous silicon layer, the island-like semiconductor layer comprising a U-shaped trough formed therein in such a way that the U-shaped trough extends completely through the N-type lightly-doped amorphous silicon layer and the N-type heavily-doped amorphous silicon layer so as to divide the N-type heavily-doped amorphous silicon layer into first and second N-type heavily-doped amorphous silicon layers respectively on two sides of the U-shaped trough and to divide the N-type lightly-doped amorphous silicon layer into first and second N-type lightly-doped amorphous silicon layers respectively on the two sides of the U-shaped trough and also to form a channel in the amorphous silicon layer at a location under and corresponding to the U-shaped trough; and the source terminal and the drain terminal are respectively in contact with surfaces of the first and second N-type heavily-doped amorphous silicon layers.