Heat resistance of Ga-doped ZnO films deposited by ion-plating with DC-arc discharge: Impact of O2 flow rate during deposition

Heat resistance of Ga-doped ZnO (GZO) films have been studied for films deposited by an ion-plating with DC-arc discharge. Influences of O₂ flow rate during the deposition and atmosphere on heat resistance was examined. Electrical properties of the GZO films changed depending on the O₂ flow rate during deposition. The minimum resistivity was obtained at the O₂ flow rate of 11 sccm. The heat resistance slightly depended on the O₂ flow rate. By controlling the deposition condition, we obtained the GZO film with resistivity of 2.5 × 10^-4 Ωcm, which was stable up to 400 °C in N₂ atmosphere, and the resistivity of 2.9 × 10^-4 Ωcm, stable up to 300 °C in air atmosphere. Although the resistivity was stable up to the critical temperature, the Hall mobility increased and the carrier concentration decreased with increasing the annealing temperature. As the result, optical transmission spectra were affected by the thermal annealing even below the critical temperature.