THIN FILM TRANSISTOR WITH REDUCED CHANNEL LENGTH FOR LIQUID CRYSTAL DISPLAYS

摘要

A liquid crystal display including an array of thin film transistors. Each thin film device in the array includes gate, source and drain electrodes. At least one of the source and drain electrodes include first and second metal layers offset with respect to one another so as to reduce the channel length of the transistors. Because of the reduced TFT channel length, the TFT channel width can also be reduced while maintaining the same ON current. Thus, the gate-source capacitance is reduced which in turn reduces pixel flickering and image retention and improves gray level uniformity. The first and second source-drain metal layers are of different materials so that the etchant for the second metal does not etch the first metal layer deposited. The TFT may be either a linear TFT or a ring-shaped TFT according to different embodiments of this invention.