Etching of SiO2 in a narrowly confined plasma of high power density

An etch process for SiO2 in a C6F14+N2 plasma at 1 Torr pressure and with a power of 10 W/ccm was examined for its etch rate dependence on gas composition, pressure, and electrode separation. Rates larger than 1 mym/min were obtained. The selectivity with respect to silicon could be made infinitely high by choosing various gas mixtures. An axial magnetic field increased the etch rate by 20%. The process was highly anisotropic. Ion and neutral mass spectroscopy was applied to illuminate the differences between this process and the conventional cathode coupled process (RIE) at pressures of 0.05 Torr. (IAF)