A Combined Cell-Level Set Simulation Method for Plasma Etching

Abstract

The invention discloses a cellular-level set unit analogy method for plasma etching. A cellular method expresses a plasma etched physical chemistry mechanism to obtain surface etching rate in a plasma etching process, and then the surface etching rate serves as a velocity field function of a level set to simulate an evolutionary process of a whole section to obtain a plasma etched section feature. A numerical computation method is characterized by having specific physical significances, being capable of distinctly depicting physical chemical phenomena in the plasma etching process, simultaneously being high in computational efficiency, good in stability and prone to expand to three dimensions, and being an efficient numerical simulation method applicable to commercialization.

Description

technical field [0001] The invention relates to numerical simulation of dry etching in the field of microelectronics, in particular to a cell-level set joint simulation 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 the feature size of the device (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 exp...

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Problems solved by technology

With the rapid reduction of the feature size of the device (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 large amount of calculation of the cell method, The mathematical foundation is not strict, the accuracy of the line simulation method is low, and it is not easy to expand to three dimensions, and the calculation efficiency of the feature simulation method is low, etc., while the level set method can establish a strict mathematical model, quickly and accurately track the change information of the interface, and can ensure the numerical accuracy. Stability, but due to its lack of sufficient physical and chemical meaning, the simulation results are often not accurate enough. The combined calculation method of the cellular level set combines the advantages of the clear physical and chemical meaning of the cellular method with the advantages of high-speed stability of the level set method , is an accurate and high-speed numerical simulation method suitable for commercialization

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