Calculation Of 3D Lithography Model Based On Rigorous Coupled Wave Analysis

With the development of semiconductor lithography technology,lithographers have higher and higher requirements for lithography processes.Therefore,various simulators have been developed,such as the traditional finite element method or finite difference space discrete method..However,these methods are quite computationally expensive and inefficient when solving the problem of 3D optical lithography.The key to solve these problems is to build a more rigorous model and a more reasonable algorithm.By reading a lot of papers,network resources and blogs related to lithography simulation,we introduced a new model in this experiment,namely the RCWA(strictly coupled wave analysis)model,which makes it very convenient to solve the electromagnetic field strength of the mask.This model introduces a vector potential,uses the vector potential to solve Maxwell's equations in the space frequency domain,constructs the eigenvalue matrix and boundary conditions,calculates the amplitude distribution of the mask layer by layer,and finally calculates the electromagnetic field strength of the diffraction model.The main research contents of this experiment include:First,the RCWA(strictly coupled wave)algorithm is studied and analyzed.The vector potential A is used to solve the Maxwell equations.Through mathematical operations such as Fourier transform and differential equations,a eigenvalue matrix is constructed and solved.Eigenvalues and eigenvectors,because the mask is divided into multiple layers,this experiment will also solve the amplitude distribution of each layer in layers,and then calculate the incident light amplitude,transmitted light amplitude,and reflected light amplitude,and then use the boundary conditions.Find the electromagnetic field strength of the mask.Secondly,after having a certain understanding of the algorithm,through detailed derivation of the formula,build a three-dimensional lithography model and write matlab code to simulate it,get the simulation results of the near field of the mask;then,in the experimental simulation results On the basis,we propose a possibility to implement mask optimization based on generative adversarial network(GAN).This experiment first introduces automatic encoder(AE),variable automatic encoder(VAE),and generative adversarial network(GAN))And the related principles of conditional generation confrontation network(CGAN),then introduced the GAN-based OPC method(GAN-OPC),GAN-based SRAF method(GAN-SRAF)and Litho GAN-based end-to-end lithography modeling principles,The design process and related algorithms are explained.In this paper,the research on the calculation method of the three-dimensional lithography model based on RCWA,compared with the traditional method,this method provides a new solution idea,which brings great convenience in mathematical calculation,and then combined with deep learning in The application of lithography simulation has proposed the theoretical basis for using masking generative networks(GAN)to realize mask optimization,which has certain theoretical and practical research significance.