Dynamics of Deposition and Removal of a Fluorocarbon Film in the Cyclic Process of Plasma-Chemical Etching of Silicon

In situ measurements were made of the dynamics of deposition and etching of a fluorocarbon film (FCF) during cyclic plasma-chemical etching of silicon using a laser interferometer. Direct measurements of the deposition and etch rates and the etch time of the FCF open up new possibilities for optimizing the cycle procedure. For example, adjusting the etch time of the FCF improves the selectivity of the etching process.