Preparation Of ZAO Target For Electron Beam Evaporation

The research of Zinc Oxide transparent conductive oxide thin film is very hot. The film has many particular properties, such as low resistivity, high optical transparency, abundant raw materials, without toxicity, cheap, high stability in hydrogen plasma, and it applied to the solar cells will not reduce the efficiency of the battery. Therefore, it is applied to solar cells as front electrodes and back reflector electrodes and it is the important way to reduce the cost of the battery.High-quality Zinc Oxide targets are necessary to obtain high-quality Zinc Oxide thin films. Researching Zinc Oxide targets that are suitable for sputtering and electron beam evaporation is the foundation to obtain high-quality Zinc Oxide thin films.In this paper, powders of Zinc Oxide and Alumina were used as raw materials. We get Zinc Oxide targets by sintering in air atmosphere and Argon atmosphere respectively. At first, adhesives were selected, then conductivity, physical and micrographs of Zinc Oxide ceramic targets were investigated in the adhesives, the mean particle size of Alumina power, sintering time and sintering gas. The result shows:1, It is good for the molding of targets and to use 2% polyethylene glycol as adhesives. It is the foundation to obtain high-quality Zinc Oxide targets.2, When the holding time of sintering last stage (1350℃) is 2.5h, sintering is full and Spinelle is less. The conductivity of targets is the best. 3, Zinc Oxide powders were mixed with two different Alumina powders with mean particle size of 2.85μm and 2nm respectively.The results showed that the lower mean particle size target has higher carrier concentration, smaller mobility, and higher resistivity.But the surface resistance is better and Spinelle is less than the other one.4, The Argon gas atmosphere is beneficial to the emergence of defects in Zinc Oxide, the carrier concentration and improving the resistivity. We get the high quality targets which resitivity is 8.76×10-4Ω·cm in Argon atmosphere. The film with electron beam evaporation which resitivity is 7.114×10-4Ω·cm and transmittance is 80%～90%.