Simulation of silicon etching through a fluorocarbon layer

Reactive ion etching (RIE) of silicon in a CF4+H2 plasma is considered by a proposed model, which includes processes of adsorption, activation, chemical reactions, relaxation, desorption, sputtering, and mixing. Transport of species through a fluorocarbon layer is explained by surface energy induced mixing. It is found that steady-state RIE rate of silicon in CF4+H2 plasma does not depend on thickness of fluorocarbon layer. The adsorption of reactive species from the plasma on the fluorocarbon layer is the etching-rate limiting process.