Gallium-doped zinc oxide targets fabricated by sintering: Impact of target quality on sputtered thin film properties

This research reports the sintering mechanism of Ga doped ZnO (GZO) ceramic targets. The GZO powders with different Ga doping concentrations were synthesized by chemical co-precipitation method and compacted to form green compacts. The green compacts underwent a normal sintering process under different temperatures. Then a series of GZO targets sintered at 1300 °C were used for depositing thin films by DC magnetron sputtering method. The influences of sintering temperature and doping concentration on the densification, structural and electrical properties of GZO targets were investigated. Results showed that Ga doping effectively promoted the qualities of GZO targets. When sintering temperature surpassed 1300 °C, the relative densities for all the targets were higher than 97%. The lowest resistivity of 2.25×10−3 Ω cm was attained on the 0.5 at% Ga doped ZnO sintered at 1300 °C. In addition, the performances of GZO thin films were greatly influenced by the qualities of their sputtering targets.