Experimental results of two dimensional spatial distribution of plasma parameters in CVD processing plasma

Two dimensional spatial distribution of plasma parameters was recently developed by using floating harmonic methods1,2. In this study, this method was applied for real plasma processing CVD reactor with H2/SiH4 gas mixture. The measured plasma uniformity was not changed a lot with RF powers and gas mixing ratios, while the plasma uniformity was dramatically changed from convex to concave profile with gas pressures. This remarkable change in the plasma uniformity could be explained by decrease of plasma diffusivity in higher gas pressure. It is expected that this method can be novel one of the diagnostic tools for both spatial profile measurement of the plasma parameters and improvement of the plasma uniformity.