The Simulation Of RIE Process Based On Monte Carlo

Reactive ion etching (RIE) technology is one of the most widely used technologies in MEMS processing technology. Simulation of RIE can help process designers obtain the different simulated results by changing the simulation conditions, such as RF power, gas pressure, etching temperature, in order to choose the best process conditions. Developing RIE simulation software can reduce the design and development costs, shorten the development cycle.In this paper, the fluid dynamics model and equivalent circuit model are adopted to determine the characteristics of the RF sheath, including the sheath voltage and electric field spatial and temporal distribution. Monte Carlo method is used to study the movement of particles in the RF sheath and get the distribution of particles, which will affect the etching of the target materials. Then the etching rate of a certain point is calculated by using the etching speed calculation formula and particle flux distribution. At last the initial level set function is adopted to obtain the evolution process of etching by solving the equation of Hamilton-Jacobi. Etching profile, under different conditions has been obtained. Simulation results show that, within the scope of 200W to 400W, the increase of RF power will accelerate the etching rate and then decline. With the increase of the pressure, the etching rate increases and peaked at about 15 pa, then decreases. The etching rate is proportional to the temperature. Finally the simulated results have been compared with the experimental results, and they are found to be in good agreement both.This paper shows that the level set method is an efficient algorithm for plasma etching profile evolution. It can easily describe complex profile shapes that may appear in plasma etching process in practical etching process. By introducing the micro-physical processes of plasma etching to the level set method, this paper provides a new method to solve the problem of huge computation in three-dimensional plasma etching simulations.