REDUCING THRESHOLD VOLTAGE SHIFTS IN AMORPHOUS-SILICON THIN-FILM TRANSISTORS BY HYDROGENATING THE GATE NITRIDE PRIOR TO AMORPHOUS-SILICON DEPOSITION

A short H-2 plasma treatment of the gate SiNx before depositing amorph ous silicon (a-Si:H) is found to significantly decrease the threshold shifts in the bias stress, inverted a-Si:H thin film transistors (TFTs ). The reduced threshold voltage shift is attributed to a plasma induc ed reconstruction of SiNx precursors leading to the removal of the wea k bonds. A prolonged plasma treatment, however, degraded the TFT chara cteristics; this was traced H-2 plasma damage which eventually generat ed a rough a-Si:H/SiNx interface. (C) 1997 American Institute of Physi cs.