Control of Fluorocarbon Radicals by On-Off Modulated Electron Cyclotron Resonance Plasma

Abstract

The CF, CF 2 and CF 3 radical densities were investigated using infrared diode laser absorption spectroscopy (IRLAS) in a CHF 3 electron cyclotron resonance (ECR) plasma with varying on-off period of the microwave source, as well as continuous wave (CW). The ratio of CF and CF 2 radical densities to CF 3 radical density was successfully controlled through variation of the duty cycle in a constant pulse width, together with the deposition rate of fluorocarbon films. Furthermore, the radical densities were discussed in comparison with intensities of emission lines F * , Ar * and H α .