| The lithography machine is the core equipment of the integrated circuit production line.The lighting system of the lithography machine is an important part of the lithography machine.The function of the lithography machine illumination system is to uniformly illuminate the lithography mask,so that the mask is accurately imaged on the wafer surface through the projection objective of the lithography machine,and uniform exposure lines are obtained.The performance of the homogenizing device is an important factor that limits the core indicators such as the uniformity of the lighting system of the lithography machine and the energy utilization rate.The homogenizing devices used in the lighting system of the lithography machine mainly include an integrator rod and a micro lens array.When the microlens array is used as the homogenizing device,the light energy loss can be reduced,the polarization characteristic of the light can be maintained,and the uniformity of illumination of a large area can be realized.Therefore,microlens arrays are commonly used as homogenizing devices in high-end lithography machines.With the continuous improvement of the resolution of the lithography machine,the requirements for the illumination uniformity and energy utilization of the lighting system are getting higher and higher.Due to the pursuit of the limit of the illumination uniformity and energy utilization,the lighting system used in the lithography machine The microlens array has extremely stringent requirements on the fill factor and surface accuracy,and the production of this device is extremely difficult.This article explores the processing technology of the cylindrical microlens array.After comparing and analyzing the processing methods of the microlens array,ultra-precision cutting technology is selected for processing.On the basis of understanding the principle of ultra-precision cutting technology,the cutting trajectory algorithm was designed,and the accuracy of the algorithm was verified;secondly,in order to improve the processing efficiency of the spherical cylindrical microlens array,on the basis of ultra-precision turning machine tools,The flying knife cutting and planing of spherical cylindrical microlens array were studied,the experimental device was designed,and the experimental platform was built.Finally,the surface shape detection method of aspherical cylindrical microlens array was studied,and the least square method was used to The aspheric cylindrical surface is fitted with surface shape,and the contour error of the machined workpiece is calculated.Mainly include the following:1.Introduce the processing methods of the micro lens array in an overview,and compare and analyze the advantages and disadvantages of different processing methods,and finally select the ultra-precision cutting technology to process the micro lens array.Next,the research results of domestic and foreign researchers using ultra-precision turning technology to process micro-lens arrays are introduced.During the investigation process,the key issues of ultra-precision turning micro-lens arrays are considered to provide a theoretical basis for the development of subsequent thesis work.2.Designed the tool path algorithm in the turning technology,proposed the sequential search method and the binary search method to calculate the turning path,and studied the selection of diamond tool parameters and the tool radius compensation.Finally,the turning path algorithm was successfully verified through experiments Accuracy and feasibility.3.In order to improve the processing efficiency of the spherical cylindrical microlens array,the spherical cylindrical microlens array was cut by flying knife cutting and planing,and a special diamond tool suitable for the processing of convex spherical cylindrical surfaces was designed.4.Since the surface shape of aspherical cylindrical mirrors is more complicated than that of spherical cylindrical mirrors,the evaluation of the surface shape of aspherical cylindrical mirrors is more important.The fourth chapter discusses the surface shape detection of aspherical cylindrical mirrors,chooses the least square method to fit the surface shape,evaluates the closest spherical and aspherical degree of the aspherical cylindrical surface,and calculates the contour error of the workpiece after processing.Calculations are carried out to provide technical support for subsequent error compensation. |
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