Optical emission diagnostics of electron cyclotron resonance and glow discharge plasmas for a-Si:H and a-SiC:H film depositions

It is demonstrated that the steady-state and kinetic characteristics of ECR (electron cyclotron resonance) and RF glow discharge plasmas can be readily monitored by OES (optical emission spectroscopy) in real time during a-Si:H and a-SiC:H film depositions using an OMA detection system. The ECR and RF glow discharge plasmas used for a-Si:H and a-SiC:H film depositions were studied by monitoring the emission of SiH, H, H₂, and CH excited states. The OES of the ECR plasma shows a strong emission at 434 nm from H, which is not detectable in the glow discharge plasma. Steady-state OES studies have established preliminary correlations between SiH and CH emission intensities and the film deposition rate. Transient OES spectra of SiH₄ and CH₄ plasmas have shown different kinetics in SiH and CH emission intensities. Transient studies of the SiH emission intensity have indicated that additional mechanisms for producing the SiH species become evident in hydrogen-diluted silane plasmas.