Study on Ozonated Solution Oxidation of Phosphorus Doped Hydrogenated Amorphous Silicon Surface for Cu-Mn Alloy Based Electrodes in Thin Film Transistor

摘要

For next generation Cu-Mn alloy based interconnects in thin film transistor liquid crystal displays (TFT-LCDs), we propose the use of an ozonated solution as a promising oxidation pretreatment of phosphorus doped hydrogenated amorphous silicon (n~+a-Si:H) surface for the self-formation of Mn complex oxide layers. We have investigated the electrical characteristics of TFTs having Cu/Cu-Mn alloy bilayer electrodes with/without ozonated solution oxidation and those having conventional Cr-Mo single layer electrodes. TFTs having Cu/Cu-Mn alloy electrodes oxidized with ozonated solution exhibit very similar transfer characteristics to those of TFTs with conventional material electrodes; however, they also show increases in threshold voltage (V_(th)) and subthreshold swing (SS) as well as slightly reduced electron mobility and on-current. We have concluded that partial and shallow Cu-diffusion into a n~+a-Si:H layer is the most likely reason for the degraded TFT electrical properties.