Improvement of the positive bias stability of a IGZO TFTs by the HCN treatment
Abstract In recent years, many researchers have attempted to improve the bias stability of amorphous indium gallium zinc oxide (a IGZO) thin film transistors (TFTs) In this study, the hydrogen cyanide (HCN) treatment was carried out to improve the positive bias stability of bottom gate a IGZO TFTs. The HCN treatment was performed using a 0.1 M HCN solution with a pH of 10 at room temperature. Before applying the positive bias stress, there were no differences in the major electrical properties, including the saturation mobility m sat threshold voltage (V th and subthreshold swing (S/S) between HCN treated and non HCN treated devices. However, after applying the positive bias stress, the HCN treated device showed superior bias stability compared to the non HCN treated device. This difference is associated with the passivation of the defect states and the surface of the back channel layer of the HCN treated device by cyanide ions.