Adsorption behavior of various fluorocarbon gases on silicon wafer surface

An analytical technique to clarifying the adsorption behavior of a fluorocarbon gas, which is one of the key steps in reactive ion etching, has been established. In this paper, we focus on the adsorption behavior of fluorocarbon gases to the silicon wafer surface to clarify the etching mechanism in order to realize etching to a high aspect ratio. Each fluorocarbon gas had surface selectivity for SiO₂, Si and the photoresist. Each fluorocarbon gas reacted differently at the silicon wafer surface. As a result, the etching mechanism could be clarified using this newly established analytical technique. Therefore, an etching mechanism will be able to be clarified by applying the newly established analytical technique to the fluorocarbon gases expected to be useful for etching of high aspect ratio and further high performance ultra large scale integrated circuit device must be realized.