Comparative Study on the Gate-Induced Electrical Instability of p-Type SnO Thin-Film Transistors with SiO(2)and Al2O3/SiO(2)Gate Dielectrics

The gate-induced electrical instability of SnO thin-film transistors (TFTs) with SiO(2)and Al2O3/SiO(2)gate dielectric layers is evaluated. The hysteresis voltage (V-hy) and threshold voltage (V-th) in the transfer characteristics of SnO TFTs depend on the sweep range and rate of gate voltage (V-GS). The TFT with an Al2O3/SiO(2)gate dielectric layer exhibit reducedV(hy)and stableV(th)compared with the device without an Al(2)O(3)layer. The introduction of an Al(2)O(3)layer between the SnO channel and the SiO(2)layer suppresses the electron and hole trapping at the channel/dielectric interface and contains mobile oxygen vacancies that counteract the hole trapping effect.