Performance of low resistivity electrode prepared by electroless plated for amorphous silicon thin-film transistors

The TFTs array fabrication process for large-area TFT-LCD has been continuously developed for simplifying processing steps, improving performance and reducing cost in the process of mass production. In this study, the hydrogenated amorphous silicon (a-Si:H) TFTs with low resistivity electrodes, silver thin films, were prepared by using the selective deposition method that combined lift-off and electroless plated processes. This developed process can direct pattern the electrode of transistor devices without the etching process and provide ease processing steps. The as-deposited Ag films were annealed at 200 ° for 10 minutes under N2 atmosphere. The results shows that the adhesion properties can be enhanced and the resistivity has been improved from 6.0 μΩ-cm, significantly decrease by 35%, of as-deposited Ag films by annealed. The thickness of Ag thin film is about 100 nm and the r. m. s roughness value is 1.54 nm. The a-Si:H TFT with Ag thin films as source and drain electrodes had a field effect mobility of 0.18 cm2/Vs, a threshold voltage of 2.65 V, and an on/off ratio of 3×104.