Innovative Manufacture Of Electron Beam Excitation Assisted Optical Microscope With Ultra-high Resolution

In biological cells,cellular functions result in localization and dynamic interaction of molecules.Three-dimensional in-situ observations of the cell organelles will benefit the understanding of life processes mechanisms to promote the research in the cellular response to physiological or pathological mechanisms,potentially promoting research and development of anti-cancer drugs by cell surface modification intervention in cancer cell proliferation,etc.As an important tool in cell biology research,optical microscope is difficult to break the diffraction limit because of diffraction limit,its resolution being over 200 nm.Considering that the traditional scanning electron microscope can not be applied to observe fluid,we conbine scanning electron microscope with electron beam excited optical microscopy to manufacture an electron beam excitation assisted optical microscope with ultra-high resolution(EEOM for short),thus enabling the instrument to observe liquid samples in ambient condition with the imaging resolution breaking the diffraction limit.The project aims at an innovative research on the design and manufacture of EEOM,containing development of some key components such as the electron source,the thin-film cathodoluminescence materials and high vacuum isolation window.The Si N thin film is pasted on the sample table using epoxy resin,then autofluorescence samples(taking Polystyrene spheres as an example)and non-fluorescence samples(taking Silica spheres as an example)are added to the atmospheric side of Si N film,respectively.Secondary electron images,backscattered electron images as well as cathode fluorescent images can be obtained together.A systematic study is proposed on the imaging of Polystyrene spheres and Silica spheres.By reference to the fluorescence characteristics of Si N film,the imaging principle is studied.Because of its high corrosion resistance,high temperature stability and good mechanical strength and so on,Si N has been widely used as the experimental carrier of TEM,SEM,AFM,XPS,EDX and other characterization.In particular,Si N can be used as a low disturbing background for SEM observation.However,the poor hydrophilicity of Si N thin films has restricted its application in the observation of water samples.The particles in the water suspension are difficult to be evenly distributed on the surface of the film.The use of plasma etching machine and UV light can only get a temporary hydrophilic effect.The study employed piranha solution(Hot concentrated sulfuric acid and hydrogen peroxide mixture)for hydrophilic treatment,obtaining the long-term hydrophilic stability of more than 24 hours.In order to enhance the fluorescence efficiency of silicon nitride membrane,series of Zn O films were prepared on a Si Nx film substrate by RF magnetron sputtering technique.Samples were then non-situ and in-situ annealed in nitrogen atmosphere,respectively.This paper systemically studies the luminescence of the prepared thin films.Luminescent intensity increases after sputtering.Compared with non-situ annealed films,in-situ annealed Zn O/Si N films contained more oxygen vacancy defects,thus showing a stronger visible light luminescence intensity.