Simulation And Experimental Verification Of Plasma Etching And Deposition

With the rapid development of integrated circuits and the decrease of chip size,the requirements for the processing precision of semiconductor technology are becoming higher and higher.Plasma etching and deposition technology is widely applied to semiconductor technology,due to its advantages such as high reaction rate,high accuracy,good uniformity and reproducibility.The process of plasma etching and deposition is actually a very complex process.It involves not only the macroscopic reaction of the chamber,but also the microscopic reaction of the sample surface.Because of the complex mechanism of plasma,the industry is mainly exploring experimental process through lots of experiments,In this way,it not only consume a lot of human cost,but also the economic cost will be very high.Based on the above reasons,we hope that we can simulate the process of plasma etching and deposition through theoretical analysis and modeling,and verify it with corresponding experiments.Using theoretical analysis,software simulation and experimental verification,the correctness of the simulation can be well verified by the combination of the three.We can use the simulation result to predict the experimental results,so that we can save economic cost and human cost.The software for plasma etching and deposition simulation can be divided into two kinds:One is a simulation software based on particle cloud grid/Monte Carlo algorithm,and the other is a multi-physical field simulation software based on fluid dynamics.Because ESI-CFD simulation software can calculate 2D/3D model,adopt fluid finite element calculation method,simulate in multi field environment,support complex boundary conditions and have abundant parameter library,etc.,the industry generally uses it to simulate application.In this paper,we use ESI-CFD as simulation software to simulate.The chamber reaction of plasma etching and deposition process and the evolution of the surface morphology of the sample are studied by different components of ESI-CFD.In the plasma etching process,C₄F₈/Ar and CF₄ are used to etch silicon oxide respectively.From the perspective of software simulation,we have studied the effects of gas flow ratio,chamber pressure,substrate bias and ICP power on electron temperature,electron density,particle density,particle energy and angle distribution and final etching rate.Thus,we can clearly see the effects of various experimental factors on the plasma etching.In the plasma deposition process,the silicon dioxide that deposited in SiH₄/N₂O mixture by PECVD.Through simulation,we qualitatively analyze the chamber temperature,chamber pressure,particle density distribution,particle energy distribution and angular distribution,and so on,and simulate the morphologies evolution of different depth/width ratios.Also we quantitatively analyze the deposition rate of the sample's surface.On the basis of simulation,the corresponding experiments are made,and the results are compared with the simulation results.The results show that the simulation and experiment are in good agreement,which can guide the experiment well.