Study Of Preparation Of High-resistance Composite Films In Microchannels And The Electrical Properties

The microchannel plate is a two-dimensional channel electron multiplier with a high aspect ratio structure,which has a wide range of applications in the fields of low light image tubes,photomultiplier tubes,camera tubes,ultraviolet radiation and X-ray detectors.The traditional lead silicate glass microchannel plate is limited by the preparation process and the choice of matrix material,and cannot meet the requirements of small aperture,high resolution,and low noise.The resistivity of the conductive layer of the advanced technology microchannel plate dynode is not easy to control and it is difficult to achieve substrate insulation.Atomic layer deposition technology has the advantages of self-limiting,precise control of thickness and low deposition temperature,which provides a new idea for the preparation of dynode conductive layer.In this paper,atomic layer deposition technology is used to prepare high-resistance AZO composite films in quartz substrate and glass microchannel array.Firstly,an AZO film was prepared on a quartz substrate,and the effects of the number of sub-cycles and the percentage of Al₂O₃ cycles on the surface morphology and electrical properties of the AZO film were studied.The effects of different annealing conditions on the sheet resistance of AZO composite films were studied.After that,AZO composite films were prepared in glass microchannel arrays to study the influence of precursor aeration time on film coating,composition,thickness uniformity and electrical properties.Finally,the effect of annealing on the resistance of the microchannel plate is explored.The research on the quartz substrate shows that the experimentally produced films are all smaller than the theoretical thickness,which proves that there is a corrosion effect during the growth of the AZO composite film.It is measured that the nucleation period of Zn O should be greater than 4,and a too small period will cause the film density to decrease.The cycle percentage of Al₂O₃ is between 25%and 50%,and the square resistance of AZO film is between 3.77×10¹¹?5.83×10¹³/?,which meets the requirements of the square resistance of the MCP conductive layer.When the number of Al₂O₃ layers of the sub-layer is greater than 2,the sheet resistance of the film will greatly increase for each additional layer.The sheet resistance of the film increases as the annealing time and annealing temperature increase.The film with a zinc-aluminum cycle ratio of 6:2 is annealed at 300?for 90 min,and the sheet resistance of the film can reach 7.25×10¹¹?/?.Studies on glass microchannel substrates show that the use of dynamic valve technology improves the film quality and saves the source material.By prolonging the precursor's ventilation time,the membrane can be uniformly covered in the microchannels.When DEZ ventilation time was 400 ms and TMA ventilation time was 480 ms,high resistance films with uniform thickness and composition could be prepared in microchannels.Structure of Zn O/Al₂O₃=7/2 film,after annealing 90 min at 800?1000 V voltage resistance under 1.68×10⁸?1.91×10⁸?,satisfies the requirement of microchannel plate body body resistance.