Research On Prepared Technology And Properties Of ZAO Ceramic Target And Thin Films

ZAO transparent conductive film which has good conductive properties, high transmittance in the visible region and inexpensive cost, etc., is expected to replace the ITO film in the current market. In this paper, the homogeneous precipitation method, co-precipitation method and the mechanical milling method were used to prepare ZAO powders, and the isostatic cool pressing was used to make ceramic green body, then atmospheric sintering processed ZAO ceramic target. In the last, ZAO transparent conductive films were obtained by the RF magnetron sputtering process, and the films subjected to annealing heat treatment in argon atmosphere. The phases of the powders and the ceramic target, morphology, compositions, and the film’s transmittance and resistivity were analyzed by XRD, SEM, TEM, DTA, EDS, spectrophotometer, and the four-probe tester. There were the following research conclusions:1. ZAO powders were prepared by the homogeneous precipitation method, co-precipitation method and the mechanical milling method, and its phase composition and characterization were analyzed. The results showed that:the powder particle sizes prepared by the two chemical precipitation methods were far less than the powders prepared by the ball-milling method; their sizes were about lOnm. The crystal structure was ZnO wurtzite structure after the crystallization treatment. But there were different degrees of reunion, and the reunion of ZAO powders prepared by homogeneous precipitation was at a lesser extent, the aggregate size was about50nm.2. the optimum sintering processes of three ceramic targets were:the sintering temperature of green body prepared by mechanical milling method was1420℃, the sintering time was2h, the target density was88%; the sintering temperature of the body made by co-precipitation method was1460℃, the sintering time was2h, the target density was90%, the radial contraction rate was10.5%; the sintering temperature of the body made by homogeneous precipitation method was1420℃, the sintering time was2h, the target density was93%, the radial contraction rate was18.5%.3. ZAO films were sputtered with different magnetron sputtering power. The results showed that:when the sputtering power ranged from200W to350W, the resistivity of the film was significantly decreased as the sputtering power increased. While the sputtering power reached400w, the film resistivity increased slightly; the transmittance decreased slightly as sputtering power increased. The average values of the transmittance in the visible range were more than85%.4. ZAO films were sputtered with different substrate temperature. The results showed that: the ZAO film resistivity significantly decreased as the substrate temperature increased, and the minimum value was2.37×10-3Ω·cm. the transmittance changed little, but the average values were over80%.5. ZAO films were annealed with different annealing temperature and time. The results showed that:the film resistivity was down then up as the annealing temperature increased. When the heat treatment temperature was250℃, the film resistivity was1.087x10-3Ω·cm; When the annealing time range was1-3h, the film resistivity was significantly decreased as the annealing time increased. When the annealing time was2h, the minimum value of the film resistivity was1.087×10-3Ω·cm. The film transmittance changed little with annealing temperature and time.