Research On Preparation Of MgZnO Thin Film Transistor And Ultraviolet Detection Characteristics

In recent years,oxide semiconductor thin film transistors(TFTs)have been widely used in the next generation of large-area new display screens due to their high electron mobility,high optical transmittance,and lower process temperature.In addition,due to its wide band gap(Eg),these thin film transistors also occupy an increasingly important position in the field of ultraviolet(UV)detectors.Among them,zinc oxide(Zn O),as an n-type semiconductor,not only has high chemical stability,but also has excellent optical and electrical properties at the same time.Therefore,application research based onZnO-based thin film transistors in the field of flat panel displays and ultraviolet detectors has attracted widespread attention.In order to maintain the inherent advantages ofZnO and eliminate the adverse effects of pureZnO,magnesium(Mg)was introduced intoZnO to form ternary Mg_xZn_1-xO as the channel material of thin film transistors.In summary,the thesis mainly focuses on the effects of sputtering power,post-annealing atmosphere and time,and growth temperature on the performance of MgZnO thin-film transistors,as well as the UV detection characteristics of MgZnO thin-film transistors with different Mg content interdigitated electrode structures.The main research work and results were as follows:1.MgZnO thin film transistors with different powers were prepared by magnetron sputtering,and the effect of different Mg sputtering powers on the performance of MgZnO thin film transistors was studied and analyzed.The experimental results showed that the overall performance of the device was best when the Mg target power was 3W.The performance of the device was:current switching ratio 1.54×10⁷,mobility 1.98cm²V^-1s^-1,and subthreshold swing 1.1V/decade.2.Using rapid annealing in different atmospheres to control thin film carriers to improve the device performance of MgZnO thin film transistors.It was found that the MgZnO thin-film transistor prepared under room temperature was more suitable to adopt low-temperature rapid annealing in air atmosphere,which can ensure low off-state current and high on-state current.The device performance was:current switching ratio 7.4×10⁷,The mobility was 3.796cm²V^-1s^-1.3.To explore the influence of different growth temperatures on MgZnO thin-film transistors,the research results showed that the overall performance of the device was the best when the growth temperature was 60?,the current on-off ratio was 3.9×10⁷,the threshold voltage was 6V,and the subthreshold swing was 0.6V/decade.4.The UV detection characteristics of the interdigitated electrode structure MgZnO thin film transistors with different Mg doping levels were studied,and the photoresponse test and comparison of the devices were carried out,and the dynamic response test under multiple photoperiods was carried out.The experimental results showed that when the Mg content was1.54%,the highest response of the device was 66.6A/W.