Research On Cone Field Emission Array Cathode Technology Of Current Stabilization

Field emission array cathodes have the advantages of wide operating temperature range,fast response,low power consumption and high current extraction density.They have broad application prospects in many fields such as displays and microwave devices,and have always been a research hotspot at home and abroad.Due to the limitations of the preparation process,the radius of curvature and the height of each emission tip are hardly exactly the same.There are large differences in the emission performance of the tip cones of different shapes.When the cathode is working,some tip cones have strong emission capability,which easily causes emission overload,which causes the sharp cones to be damaged,resulting in the destruction of the entire field emission array and severely limiting the field emission array cathode applications.In order to improve the stability of the field emission array cathode,this paper has done the following work:1.The use of resistive voltage divider characteristics of the resistance flow layer structure design.Calculate the general thickness and resistivity requirements of the steady flow layer and use an amorphous silicon film as the stabilizing layer.2.The thermal stress distribution of the cathode with a steady flow layer structure was simulated by COMSOL,and the relationship between the thickness of the steady flow layer and the thermal stress distribution of the tip and the best thickness parameter of the steady flow layer were obtained.3.The effects of different preparation parameters and post-processing parameters on the electrical properties of the stabilizing layer were studied.Amorphous silicon thin film was prepared by electron beam evaporation method.The effects of different evaporation power and substrate temperature on the resistivity of amorphous silicon stabilizing layer were studied.The effects of different annealing temperature and annealing time on the resistivity of amorphous silicon stabilizing layer were studied.Combined with software simulation results,the best preparation parameters were obtained.4.The preparation process of Spindt type field emission array cathodes was studied.Spindt-type cathodes with stabilizing layer structure were prepared by electron beam evaporation.The key preparation process and the effects of different preparation parameters on the tip-shaped morphology were studied.A Spindt-type array cathode with excellent topography performance was finally prepared.5.The performance of the field emission array cathode was tested.The test circuit was designed and built,and the emission performance test and steady flow effect were analyzed for the prepared field emission array cathode.The opening voltage of the cathode with the steady flow layer is 112 V,the threshold voltage is 148 V,and after continuous working 160 h,the emission current of the cathode decreases,but it still works normally.