Possibilities and limitation of SiO/sub 2/ etching with parallel plate RF plasma

The RIE-Lag in a parallel plate RF plasma is examined and the possibilities and limitations of parallel plate RF plasma etching of SiO/sub 2/ are evaluated. It is found that RIE-Lag is due to nonuniform CF/sub x/ radical distribution and Ar ion sputtering angle. Therefore, the countermeasures for RIE-Lag are: optimize the gas flow distribution, use a wafer chucking system without a clamp, maintain the chamber condition with an upper and lower electrode temperature, and employ a larger process chamber for more uniform radical density.