Short-channel amorphous-silicon TFT for AMOLED

We studied short-channel amorphous-silicon thin-film transistors for active-matrix organic light-emitting diodes (OLED). For bottom-emission OLED, the channel length should be reduced to have a high aperture ratio. We studied the performance of a-Si:H TFT as a function of channel length. The field-effect mobility decreases with decreasing channel length because of the contact resistance. One-μm channel length was achieved with the use of a conventional photolithographic method. The field-effect mobility and threshold voltage of an a-Si:H TFT with a short channel size of 1 μm were found to be 0.36 cm/V·s and 4.8 V, respectively.