大面积VHF-PECVD反应室喷淋式平板电极间电场和流场数值模拟

Numerical simulation of electric field and flow field between large-area parallel-plate electrodes of VHF-PECVD Reactor

以大面积喷淋式平板电极甚高频等离子体增强化学气相沉积(VHF-PECVD)反应室为研究对象,利用FlexPDE和CFD-ACE+商业软件,对反应室电极间的电场和流场分布进行了数值模拟。根据数值模拟结果可知:对于大面积喷淋式平板电极VHF-PECVD反应室,电极间气体流速分布呈现管流特征,而气压分布和电场分布具有类似的分布规律,即在大面积电极中央区域电场较强气压较高,而电极边缘区域电场较弱气压较低;另外,反应室采用喷淋式平板电极进行反应气体馈入,气体总流量、工作气压和电极间距是调节电极间气压分布均匀性的重要参量,采用大电极间距、高工作气压,以及小的气体总流量有助于获得均匀的气压分布。

The VHF-PECVD （very high frequency plasma enhanced chemical vapor deposition） reactor with large-area spraying parallel-plate electrodes was investigated via a numerical simulation of the distributions of the electric field ands. flow field between the electrodes by use of the commercial software FlexPDE and CFD-ACE ＋. The numerical simulation results showed that the distribution of gas flowrate between such electrodes presents the characteristics of pipe flow and both the electric field and gas pressure are distributed similarly, ie., the electric field intensity is high with high gas pressure in the central part of electrodes, while the electric field intensity is low with low gas pressure in the edge part. In addition, with the reaction gas fed to the reactor via the spraying parallel-plate rleetrodes, the total gas flowrate, working gas pressure and the gap between electrodes are all the important parameters for readjusting the uniformity of the distribution of gas pressure between electrodes. So, the big gap between electrodes, high working pressure and small total gas flowrate benefit the uniform distribution of gas pressure between electrodes.