FINE PATTERN ETCHING OF SILICON USING SR-ASSISTED IONIZATION OF CF4 GAS

A new etching method of semiconductor materials using ionization of CF4 gas by synchrotron radiation (SR) and acceleration of SR-generated ions by external electric field is proposed. The SR is irradiated parallel to the substrate and the electric filed is applied perpendicular to the substrate. The dominant quasi-stable gas-phase ion is CF3+ which is measured by photoionization mass analysis. This method is applied to etch silicon substrate having resist mask and fine pattern of 0.1μm line and space is successfully fabricated.