Research On The Preparation Of MgAl₂O₄ Film And Its Properties

As the core component of liquid crystal display?LCD?and organic light-emitting diode display?OLED?,the TFT array has always been an important research object for researchers.Amorphous oxide semiconductor thin film transistor?AOS-TFT?is favored due to its high mobility,transparent in visible region,low preparation temperature and stability.At present,TFT must be produced under high vacuum in industry.The vacuum equipment is very expensive.There are many oxygen vacancies in the process of thin film deposition,which leads to the decline of device performance.The anodic oxidation method used in this paper works in air atmosphere at room temperature,which is easy to be operated and cost less.Based on the results of the laboratory,ammonium tartrate glycol solution was used in anodic oxidation of Mg-Al alloy films with different atomic ratios exploring the structure and properties of MgAl₂O₄ films.The main work and research results of this paper are as follows:1.The parameters was unchanged except the electron beam of the Mg target when evaporated Mg-Al alloy films by electron beam.The test results show that the roughness of the films increased after dropped to the minimum with the increasement of electron beam,but the concentration of Mg still increased.2.The films with the same atomic ratio oxidized at different oxidation current densities and constant pressure of 85V for 1.5 hours were tested for AFM?EDS?XRD.The surface of the film is more smooth and the uniformity is better when the oxidation current density is large.The smaller the oxidation current density is,the worse the film mass is,and the more Mg is lost to the electrolyte.When the oxidation current density is 1.2 and 1.5mA/cm²,the composite oxide thin films with smooth surface can be obtained.The XRD atlas shows the films prepared by anodic oxidation are amorphous.3.The leakage current test results indicate that the insulation performance and stability of the film can be improved by increasing the density of the oxidation current properly.The leakage current of the composite metal oxide film oxidated in 1.2mA/cm² optimally is10^-7A/cm²,and the maximal breakdown voltage is 25V.4.Comparing the J-V characteristic curves of different atomic ratio films with the same oxidation current density,it is found that when the ratio of Mg and Al atomic is 0.11 and 0.15,the insulation is the best,the leakage current density is 10^-7A/cm² magnitude,and the breakdown voltage is relatively high.5.The leakage current of the film containing less Mg oxidized by small oxidation current density decreased obviously after annealed at 300?,but the breakdown voltage increased from 15V to 22V.Large scale films with large oxidation current density oxidation are homogeneous and compact,and the defects are less.After annealing,the insulation properties are basically unchanged.The films containing more Mg oxidized by larger oxidation current density are homogeneous and compact with few defects.The insulation performance is basically unchanged after annealing.