Study On The Preparation And Properties Of MgZnO Targets

Mg_1-xZn_xO alloy has attracted much attention because of its potential applications on Zn O based TFT and photodetectors in ultraviolet band regions. As MgZnO-TFT active layer, the band gap of MgZnO film larger than Zn O, it will promote the application of transparent electronics due to the advantages of cubic MgZnO film in crystal quality and the coverage of solar blind ultraviolet band regions（220²80nm）, Further study of cubic MgZnO is necessary for fabricating high quality UV photodetectors. In addition to controlling the preparation of films of various process conditions, the preparation of high-quality sputtering target is extremely important in order to obtain a thin film with excellent performance. In this paper, the MgZnO ceramic target was prepared by pressureless sintering method with Zn O, and Mg O powder as raw material. The properties of MgZnO ceramic target was invested in the milling time, sintering temperature and doping concentration of Mg O respectively. MgZnO thin film was prepared by rf-magnetron sputtering using MgZnO target. The main results were as follows:1.The crushing effect of MgZnO powder was obvious in the former 36 hours with the particle size from 1.5μm quickly dropped to 350 nm while reduced with a further increase in milling time. Taking many factors into consideration such as the energy of production, the best milling time for MgZnO targets was 36 hours. The target with high density, a very small porosity, and fuzzy grain boundaries was prepared with MgZnO powder milled for 36 hours.2.Explore the effect of sintering temperature and doping concentration on the target shrinkage, density, bending strength, hardness and other properties. The results showed that, the optimal sintering temperature increases with the increase of Mg O concentration, When doping ratio is 0.12 and 0.2, the optimal sintering temperature is 1450℃ and 1500℃, respectively.3.At the same sintering temperature, the density would increase with the increase of Mg O concentration but the bending strength first increased and then decreased. The maximum bending strength can reach 94.56 MPa when doping ratio is 0.12.The hardness increase with increasing Mg O concentration the Vickers hardness is 152HV0.3 when doping ratio is 0, and the hardness would increase to 364.045HV0.3 when doping ratio is 0.4.4. The sheet resistance gradually decrease with doping Mg O ratio increased, the resistance is 819.36 Ω when doping ratio is 0 but it reduced to 30 MΩ when doping ratio is 0.4.5. MgZnO thin film prepared by rf magnetron sputtering. XRD analysis showed when x≤0.2 it was Only Zn O phase with good crystalline, the preferred orientation of（200） was obvious. With increasing levels of Mg O, the film transmittance and the band gap increases. When x=0.2, the visible light transmittance of 92.42%, the band gap of 3.98 e V.