Study of high aspect ratio etching in silicon by a mixture of SF6/O2 using a 2-D model based on a Monte Carlo approach.

Abstract

ABSTRACTThe subject of this paper is to describe and comment on results from an etching model based on Monte Carlo method. It calculates the temporal profile evolution of the silicon substrate under an SF6/O2 plasma chemistry and a cryogenic process. This work was conducted in correlation with an experimental set-up to ensure the validity of the final results. Some in-situ measurements obtained in the gas phase allowed estimation of the incident kinetic parameters such as main ion and neutral fluxes. Collisionless sheath model is connected to the surface model to determine energetic and angular ion distribution functions. The study focuses on final properties of deep and thin trenches used in new power components. The development of a simulation tool appears as an useful mean to understand the role of certain parameters not easily controlled by the etching machine. In this article, results concerning the topography and defects usually met during such an etching process are shown and discussed.