Analysis and Design of Flow Field for Precursor Feeding in a PECVD System

10.6567/IFToMM.14TH.WC.PS3.003

H. W. Tsai；K. H. Yang；K. L. Pan

Atmospheric pressure ； Simulation ； Flow field ； Plasma ； CVD

Proceedings of the 14th IFToMM World Congress

14th-5（2015 / 11 / 06）

105 - 110

英文

In a plasma-enhanced-chemical-vapordeposition (PECVD) system, the uniformity of coated film is influenced greatly by the upstream flow conditions. To understand the flow field and help improve the coating uniformity, we studied the pathlines of precursor droplets around the plasma head, knowing that the performance could be enhanced by improved mixing and temperature distribution in the flow field. The commercial software ANSYS-Fluent was used for analyzing the distributions of precursors and driving gas entering the plasma reaction chamber, as well as the distributions of temperature and droplets in the hot zone around the arc. Since the temperature near the heating source in the chamber could not be measured by the existing experimental instrument, the temperature was only measured at the chamber outlet. As a result, the temperature profile inside the chamber was simulated under the limited conditions as given. Specifically, by assuming different temperatures on the heating surface, various temperature distributions can be observed and the one that is closer to the similar condition at the outlet can be identified as the reasonable profile. Accordingly, the temperature distribution around the heat source inside the chamber can be determined. It was found that, with only one inlet for the entrance of precursor droplets to the plasma chamber, non-uniform temperature distribution at the outlet was significantly formed, along with a stream swirling outwardly toward downstream. The distribution of temperature at the outlet can be substantially improved by increasing the number of gas inlets to plasma region and addition of a perforated plate at the outlet.