US Patent 7507612 Flat panel display and fabrication method thereof

A flat panel display and fabrication method thereof. The present invention uses four etching processes to define a second conducting layer, a doped semiconductor layer and a semiconductor layer. The first etching process is a wet etching using a first resist layer to etch the second conducting layer. The second etching process is executed with an etchant comprising oxygen to etch the doped semiconductor layer and the semiconductor layer, and the first resist layer undergoes ashing during etching so as to become a second resist layer with a channel pattern. The third etching process is another wet etching, and the second conducting layer is etched again using the second resist layer as the etching mask. The fourth etching process is executed to dry etch the doped semiconductor layer using the second resist layer as the etching mask.