Chemical dry etching of si substrate in a discharge flow using Ar/CF4 gas mixtures

F atoms were generated by a low-power microwave discharge of various Ar/CF4 mixtures in a fast discharge flow. They were used for chemical dry etching of Si substrate at room temperature. The Variation of etch rate was measur ed as a function of the microwave power, the Ar or CF4 flow rate, and the d istance between the center of discharge and the substrate, in order to dete rmine the optimum conditions. The maximum etch rate was about 700 Angstrom/ min at a microwave power of 80W an Ar flow rate of 3000 seem, a CF4 flow ra te of 70 seem, and a distance between the center of discharge and the subst rate of 10 cm. A thin CmFn polymer was deposited on the etching edge at hig h CF4 flow rates of 80-100 seem.