Study On FEA Stabilized Current Layer By MIC Method

Compared with the hot cathode,the field emission cold cathode has the characteristics of short response time,large emission current and low working temperature,therefore it has broad prospects,including flat panel display,microwave devices,vacuum microelectronic devices and other fields.However,there are also problems in the production process,such as production is difficult to achieve consistent emitter morphology and removing the sacrificial layer when the tip is easy to fall off,the micro tip morphology of emission current caused by the difference is not uniform,leading to the short circuit gate cathode emitter is burned.Among the various of cold cathodes,Spindt cold cathode structure is the most mature preparation process,and is the most stable performance,the maximum emission current density of the field emission cathode structure,but it also has some problems,such as the launch cone uneven,Micro-tip off,resulting in uneven current transmission,cathode performance instability.In this paper,the steady flow layer of the traditional Spindt field emission structure is designed as a p-n junction structure.The sacrificial layer is metal Al,the emission layer is metal molybdenum,and the performance of the steady-current layer is optimized by MIC.Therefore,when the anomalous emission occurs,the abnormal emission of the cone can be controlled by the one-way conductivity of the p-n junction,thereby protecting the entire emitter array.The main research include: the use of electron beam evaporation equipment to prepare the steady flow layer,followed by MIC method to optimize the performance of the steady layer,including changes in different annealing parameters and n silicon thickness;find the best parameters to find the best performance after the stability.And then the thickness of the sacrificial layer and the thickness of the emission layer were studied to find the optimum vapor deposition sacrificial layer angle and the optimal emission layer thickness.After the production of the sacrificial layer and the emission layer,the cathode is hydrogenated to improve the surface activity of the cone;finally,the cathode array is encapsulated and tested for emissivity.Certain conclusions have been achieved as follow:(1)During the MIC method,the optimum annealing parameters were as follows:n silicon thickness is 30 nm,nickel film thickness is 30 nm,coating temperature is140?,chamber vacuum is 2×10-4Pa,annealing temperature is 500?,annealing time is4 h,N2 flow rate of annealing is 0.5L/ min.(2)for the sacrificial layer,the best oblique angle is 37°,the rotational speed of the oblique steam is 48rev/min,the removal time of sacrificial layer is preferably30 min.(3)for the emission layer deposition,the optimal evaporation current is 45 mA and the voltage is 8.93 KV,the best coating temperature is 180?.(4)After the hydrogenation treatment,the transmittance of the cathode is tested.The field emission current is 5.5mA,and the abnormal emission of the cone is greatly reduced to ensure the stability of the emission.