C4F8 / O2공정기체와 E-ICP를 이용한 산화막 식각

초록

Novel Enhanced Inductively Coupled Plasma is applied to etch SiO2. Effect of O2 or Ar addition to C4F8 gas is monitored by Optical Emission Spectroscopy and Quadrupole Mass Spectrometer. It is fund that Ar or O2 dilution to C4F8 increases F emission intensity and decreases CF2 intensity. However, the ac frequency to the Helmholtz coil decreases the F intensity and thus increases CF2/F ratio. By adjusting the ac frequency, the optimum etch rate and PR to SiO2 selectivity can be obtained in E-ICP.