Effect of Nitrous Oxide High Pressure Annealing on the Performance of Low Temperature, Soluble-Based IZO Transistors

The effects of oxygen (O
₂
) and nitrous oxygen (N
₂
O) high pressure annealing (HPA) on soluble indium-zinc oxide (IZO) thin-film transistors (TFTs) were compared. The N
₂
O HPA treatment produced superior device performance compared with the O2 HPA treatment. The N
₂
O HPA-treated device exhibited a reasonable μSAT, low SS, Vth, and high ION/OFF ratio of 1.0 cm
²
/Vs, 0.09 V/decade, 1.4 V, and 2.3×10
⁷
, respectively, even at a temperature as low as 200 °C. This improvement was attributed to the supply of reactive oxygen atoms from N2O molecules, leading to the reduction of oxygen vacancies, and a decrease in the impurity concentration of the resulting soluble IZO film.