Development of Discharge-Flow Type of Chemical Dry Etching Apparatus

A discharge-flow type of chemical dry etching apparatus was developed in order to study the etching processes of Si(1,0,0) and SiO_2 substrates at a room temperature. No etching of Si and SiO_2 substrates occurred in the Ar discharge flow, when such reactive species as CF_2, CF_3, and CF_3^+ were produced from the Ar(^3P_<0,2>)/CF_4, Ar^+(^2P_<1/2,3/2>)/CF_4, and Ar^+*/CF_4 reactions 1cm upstream from the substrates. When F atoms were produced from a microwave discharge of Ar/CF_4 mixtures about 10cm upstream from the substrates, the selective etching of Si and SiO_2 occurred. The etching rates of Si and SiO_2 were about 700 and 70 Å/min, respectively