Comparative Study on the Gate‐Induced Electrical Instability of p‐Type SnO Thin‐Film Transistors with SiO2 and Al2O3/SiO2 Gate Dielectrics

Abstract

The gate‐induced electrical instability of SnO thin‐film transistors (TFTs) with SiO2 and Al2O3/SiO2 gate dielectric layers is evaluated. The hysteresis voltage (Vhy) and threshold voltage (Vth) in the transfer characteristics of SnO TFTs depend on the sweep range and rate of gate voltage (VGS). The TFT with an Al2O3/SiO2 gate dielectric layer exhibit reduced Vhy and stable Vth compared with the device without an Al2O3 layer. The introduction of an Al2O3 layer between the SnO channel and the SiO2 layer suppresses the electron and hole trapping at the channel/dielectric interface and contains mobile oxygen vacancies that counteract the hole trapping effect.