Research And Design Of Scanning Electron Microscope Scanning Systems

Nowadays,scanning electron microscope(sem)is one of the most important instruments which is used to analyze in the world,and it is also one of key scientific research project.When electron beam bombards on the surface of sample after focusing,it will generate electrical signal which is used to be create image.It is often used to measure and research the micro-structure of the sample.Scanning electron microscope(sem)is a high-tech product of modern science and technology which is combined of electron optics,material science,precision machinery,computer technology,image processing technology.The paper focuses on designing a new type of image data acquisition and display system,which provides high accuracy,a wide range of magnification,a variety of scanning speed.The content of this thesis mainly includes three aspects.On the one hand is to design and wind the scanning coil;On the other hand is to design the hardware of the system.There are two parts in the design of hardware which are circuits for controlling software and the circuit for realizing the respective functions.Circuits for controlling software include the circuit for controlling scanning resolution,the circuit for controlling magnification and the circuit for controlling scanning offset.The circuit for realizing the respective functions is to control scanning magnification.Then I describe the design and improvement of the algorithm of scanning resolution.Combined with MFC,we finally conducted debugging and completed the correction of magnification,and we analyzed problems occurred during the debugging and proposed the corresponding solution.The main work of this paper is:(1)Studying the principle of scanning coil and completing production of the scanning coils.By observing the effect of image after debugging,we verified functions of the coil and finalized turns of the scanning coils;(2)I am involved in the design of hardware circuits for controlling scanning,including the circuit for controlling scanning resolution,the circuit for controlling magnification and the circuit for controlling scanning offset;(3)Analyzing the obtained image and improving algorithm of signal generation for FPGA-based.Simultaneously,we improved the circuit for controlling sweep amplitude;(4)Participating debugging and I am mainly responsible for adjustment and correction of magnification.(5)Analyzing the results of imaging and drawing up relevant measures for various problems.