Improvement in switching characteristics and long-term stability of Zn-O-N thin-film transistors by silicon doping

The effects of silicon doping on the properties of Zn-O-N (ZnON) films and on the device characteristics of ZnON thin-film transistors (TFTs) were investigated by co-sputtering silicon and zinc targets. Silicon doping was effective at decreasing the carrier concentration in ZnON films; therefore, the conductivity of the films can be controlled by the addition of a small amount of silicon. Doped silicon atoms also form bonds with nitrogen atoms, which suppresses nitrogen desorption from the films. Furthermore, Si-doped ZnON-TFTs are demonstrated to exhibit less negative threshold voltages, smaller subthreshold swings, and better long-term stability than non-doped ZnON-TFTs.