Patent ID: 7572668

Claim:
A flat display device having an organic thin film transistor formed by the following method: forming a gate electrode on a substrate; forming a gate insulating film on the substrate; forming source and drain electrodes on the gate insulating film; forming an organic semiconductor layer on the substrate; selectively forming a mask material on a portion of the organic semiconductor layer; and patterning the organic semiconductor layer by a dry etching method using the mask material; wherein the flat display device comprises a plurality of pixels arranged in a matrix shape having rows and columns, each of the pixels having at least one organic thin film transistor, wherein the organic thin film transistor comprises one or more gate electrodes, one or more source electrodes and one or more drain electrodes, and a semiconductor layer, and the semiconductor layer has a box shape, a line shape extended in a row or column direction, or a mesh shape extended in row and column directions corresponding to at least the source and drain electrodes and a portion between the source and drain electrodes.