A 10–100 µ s modulated electron cyclotron resonance (ECR) plasma is discharged to control the generation of reactive species in high-density, low-pressure plasma. The density ratio of CF2 radicals to F atoms in the CHF3 plasma correlates well with the pulse duration. This is because the generation of reactive species in the ECR plasma depends on time (10–100 µ s). Moreover, we found that a collimated ion flux was generated in the pulsed plasma. This method achieves a high ratio of SiO2 etching selectivity to Si etching and eliminates microloading effects during SiO2 contact hole etching.
ASJC Scopus subject areas
- Physics and Astronomy(all)