The Electrical properties of Atomic Layer Deposition of ZnO:N Thin Film Transistors by Ultraviolet Exposure

摘要

Recently, transparent and flexible displays have been intensively studied due to large industrial needs (1). For this purpose, transparent oxide semiconductors have been proposed as an active channel layers of thin film transistors (TFTs) replacing amorphous silicon due to its optical and electrical limitations such as opaqueness and low mobility (2-3). Especially, Zinc oxide (ZnO) is considered as an attractive candidate due to their excellent properties including high transparency, high mobility, and good processibility. So far, relatively high field effect mobility and good on-off current ratio (Wloff) were reported for the ZnO TFTs prepared at low deposition temperature. However, physical vapor deposition (PVD) such as direct current (DC) or radio frequency (RF) sputtering has been the mainstream for the fabrication method for ZnO active layers for TFTs. However, it has been reported to have strong partial oxygen pressure dependancy on film resistivity, resulting that the threshold voltage is difficult to control.