Three-dimensional calculation method for evolving plasma etching section

Abstract

The invention discloses a three-dimensional calculation method for evolving a plasma etching section. The three-dimensional calculation method comprises the following steps of: during the evolution of the plasma etching section, describing the shape of an etching initialization section by using an initial level set function, correcting the initial level set function through a re-initialization function, further fitting a speed field required during the whole evolution process through angle distribution and energy distribution of ions in a plasma flow, and forming a complete level set evolution equation; and finally, solving the level set evolution equation through a corrected Godot's formula to obtain the complete evolution process of the section. The three-dimensional calculation method for evolving the plasma etching section has the advantages of strict mathematical foundation and easy obtaining of geometrical information, high computational efficiency and saved internal memory, strong numerical stability and easy convergence, simplicity in expanding from two-dimension to three-dimension and easy realization of programming. The three-dimensional calculation method for evolving the plasma etching section solves the problems that the traditional three-dimensional calculation method for the etching section has the disadvantages of low computational efficiency, poor stability and shortage of mathematical foundation, and is an efficient calculation method suitable for commercialization.

Description

technical field [0001] The invention relates to numerical simulation of dry etching in the field of microelectronics, in particular to a three-dimensional calculation method for plasma etching profile evolution. Background technique [0002] Since the birth of the first integrated circuit in 1961, IC has become an indispensable technology in human life. The development of industrial products such as computers, mobile phones, airplanes, automobiles, and ships cannot be separated from IC. In recent years, with the rapid development of electronic products, the device size of electronic systems (MEMS) and integrated circuits (IC) has also been continuously reduced, which puts forward higher requirements for the etching process. With the rapid reduction of device feature size (doubling every year and a half), the etching process has also changed from the previous wet etching to the current dry etching (plasma etching), and then due to the dry etching The etching experiment is ex...

AI Technical Summary

Problems solved by technology

With the rapid reduction of device feature size (doubling every year and a half), the etching process has also changed from the previous wet etching to the current dry etching (plasma etching), and then due to the dry etching The etching experiment is expensive and takes a long period, so the numerical simulation of the plasma etching process is extremely important

[0003] At present, the methods that can be used for plasma etching process simulation generally include cell method, line simulation method, ray simulation method, and feature simulation method, but these simulation methods themselves have some shortcomings, such as the cell method has a large amount of calculation, The mathematical foundation is not strict, the accuracy of the line simulation method is low, and it is not easy to extend to three dimensions, and the calculation efficiency of the feature simulation method is low, etc., while the advantage of the level set method is that it can establish a strict mathematical model, quickly and accurately track interface change information, and Can guarantee the stability of the value

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