Consistent Performance ZnO TFT Based Single Transistor Nonvolatile Memory with Minimal Charge Loss

This article reports transparent bottom gate ZnO TFT based single transistor nonvolatile memory (NVM). Here current voltage hysteresis of this TFT structure has been thoroughly explored, where acceptor trap in the channel captures electrons during forward scanning resulting into threshold voltage hike in reverse scanning. This mobile charge carrier capture and release at the channel and oxide interface have been implicated in hysteresis. Additionally, it is validated using different geometrical and device parameter variations of TFT, such as channel length, temperature variation, oxide thickness, and energy level. The current I_ON/I_OFF ratio was found to be in the range of ~ 10⁹, which was responsible for the rapid switching memory speed. In addition, it was observed that the threshold voltage is impacted by programming and erase operations for various time steps. Moreover, the prospective use of the proposed NVM had a retention time for memory more than 10 years.