Dear MEMs enthusiastists, One of my Collegues is trying to etch both Silicon Nitride and Silicon Dioxide using a 'single step' Plasma Etch Chemistry'. The 'catch' is that the Plasma Chemistry MUST etch Nitrde and Oxide at a similiar rate, i.e, a selectivity close to 1:1. I suggested to him to lower the POWER and introduce a small percentage of SF6. The system he uses is a RIE etcher. regards, phil lau