Influence of activated polymer on the etching rate of silicon in CF4+H2 plasma

The reactive ion etching (RIE) of silicon in CF4+H2 plasma is considered. The influence of activated polymer on the RIE rate of silicon in CF4+H2 plasma is determined by extrapolation of experimentally measured kinetics of the etching rate. It is found that increased adsorption of CF2 radicals suppresses the RIE rate of silicon in CF4+H2 plasma during the initial stages of the etching process. The formation of activated polymer becomes pronounced when adsorbed CF2 radicals are slowly activated. The activated polymer intensifies the etching reaction and enhances the etching rate. C atoms, produced during the reaction, contribute to the formation of polymer on the surface. The increased concentration of the polymer suppresses the RIE rate of silicon in CF4+H2 plasma at later stages of the etching process.