The sintering behavior, microstructure, and electrical properties of gallium-doped zinc oxide ceramic targets

The properties of sputtering targets have recently been found to affect the performances of sputtered films and the sputtering process. To develop high-quality GZO ceramic targets, the influences of Ga2O3 content and sintering temperature on the sintering behavior, microstructure, and electrical properties of GZO ceramic targets were studied.The results showed that the increase in Ga2O3 content from 3 wt% (GZO-3Ga) and 5 wt% (GZO-5Ga) not only inhibited the densification but retarded grain growth. During sintering, ZnGa2O4 phase formed before 800 °C, and Zn9Ga2O12 phase was found after sintering at 1000 °C. Moreover, after sintering at 1200 °C, the number of Zn9Ga2O12 precipitates increased at the expense of ZnGa2O4 and ZnGa2O4 disappearing completely. The relative density, grain size, and resistivity of GZO-3Ga sintered at 1400 °C in air were 99.3%, 3.3 μm, and 2.8 × 10−3 Ω cm, respectively. These properties of GZO ceramics are comparable to properties reported in the literature for AZO sintered in air.