Study On Electrical Properties And Preparation Process Of Thin Film Dynode By ALD

The traditional glass microchannel plate adopts the preparation technology of lead glass hydrogen reduction,so that the resistance characteristics of the striking conductive layer and the secondary electron emission characteristics of the emissive layer are simultaneously affected and limited by the matrix material,and the positive ion feedback effect brought by the process of hydrogen reduction also affects the lifetime of the devices.The thin film dynode microchannel plate is a new technology developed in recent years,which can improve the electronic gain and reduce noise.The microchannel plate has an aspect ratio of 40-50,and it is generally difficult for a thin film technique to deposit a uniformly coated film on the inner surface of the channel.At present,ALD technology is considered to be the most suitable process for the preparation of microchannel plate film dynode.However,for the high aspect ratio microchannel plate film dynode ALD preparation technology and electrical properties,further systematic research work is needed.In this thesis,we firstly deposited AZO thin films on a flat substrate by atomic layer deposition and investigated the effects of zinc-aluminum lamination ratio and sub-circulation coefficient on the surface morphology and electrical properties of AZO thin films.Secondly,we used ALD process to prepare AZO thin film as the conductive layer and the secondary electron emission layer of the Al₂O₃ film on the glass microchannel plate.The process of forming the getter film with good coating on the surface of the high aspect ratio microchannel was emphasized and a thin film microchannel device was fabricated.Finally,the resistance and electronic gain of the sample microchannel plate device were tested by a photoelectron multiplying device vacuum dynamics test system.The results showed that when the zinc cycle ratio is 50%and the sub-circulation coefficient is?8,the AZO film sheet resistance is at the order of 10¹²¹0¹³?/?,which can meet the requirements of the resistance of the microchannel plate galvanic conductive layer.The dynamic disc valve control was used to optimize the gas source over-consumption problem.For Zn:Al laminates with 6:6,cycle period of 200,reaction time of 10s'ALD high aspect ratio microchannel plate film dynode,in theory,the consumption of DEZ gas source and TMA gas source can be reduced to 3.16 g and 1.85 g respectively.Through the optimization of ALD process,the gas source consumption was greatly reduced,the adjustment range of reaction time is increased,and the coating property of the high aspect ratio microchannel ALD filmwas improved.At 800 V operating voltage,the measured resistance was 200-600 M?and the electronic gain can reach 1000.