Stability of zinc nitride thin-film transistors under positive and negative bias stress

Abstract

In this work, the electrical stability of zinc nitride (Zn3N2) Thin-film Transistors (TFTs) under negative bias stress (NBS) and positive bias stress (PBS) is presented. The Zn3N2 TFTs were fabricated on plastic substrates. Spin-on glass was used as gate dielectric. The threshold voltage shift (ΔVT) and its recovery are analyzed during a long stress time and after a period of rest. The hysteresis of the transfer characteristics after the electrical stress is also analyzed. In order to explain the mechanism of instability in the Zn3N2 TFTs, MOS capacitors were fabricated and characterized under NBS and PBS. The behavior exhibited in MOS capacitors under NBS and PBS, is in agreement with the ΔVT exhibited in the Zn3N2 TFTs under NBS and PBS, respectively.