High-Efficiency PFC Abatement System Utilizing Plasma Decomposition and Ca(OH)$_{2}$ /CaO Immobilization
In order to minimize contributions to global warming, it is important to develop a perfluorocompound (PFC) abatement system that can remove PFCs effectively with low electric power. We have developed a new PFC abatement system consisting mainly of a 2-MHz ICP plasma source and two Ca(OH)2/CaO columns operated under a decompression pressure. Reactive fluorinated compounds including SiF4 are immobilized in the Ca(OH)2/CaO columns without a water scrubber. Stable compounds such as CF4 are excited by the 2-MHz ICP plasma. When the emissions from an Si oxidation film etching process chamber were treated by this abatement system, F2 equivalent removal efficiency was 99.6%, which was about one order of magnitude larger than that of a conventional abatement system. But the CO2 equivalent removal efficiency was calculated to be 91.4% because over 95% of CO2 equivalent emissions were caused by the plasma source power consumption of 2.4 kWh. It means that minimization of the plasma source power consumption, depending on PFC emissions, is a very effective method of minimizing contributions to global warming in a manner similar to improving the PFC removal efficiency.
Process optimization and PFC emission reduction using a c-C/sub 4/F/sub 8/ chamber cleaning process on a novellus concept 1 dielectric PECVD tool
While the new generation of chemical vapor deposition (CVD) tools adapts NF/sub 3/ as a chamber clean gas to reduce perfluorocompound (PFC) reductions, process optimization (C/sub 2/F/sub 6/) and alternative C/sub x/F/sub y/ clean chemistries are options for the installed-base tools. From a previous study comparing the various C/sub x/F/sub y/ chamber clean chemistries, we further conducted a production test in a 150-mm wafer fabrication facility comparing the best alternative C/sub x/F/sub y/ clean chemistry (C/sub 4/F/sub 8/ clean) with an optimized C/sub 2/F/sub 6/ clean process on a Novellus Concept 1 Dielectric tool running TEOS-based SiO/sub 2/ CVD. Gas flow rates, chamber pressure, and oxygen volume percentages were studied as variables to develop an optimal c-C/sub 4/F/sub 8/ process recipe for maintaining or improving cleaning efficiency while reducing gas consumption and PFC emissions compared to the optimized C/sub 2/F/sub 6/ process. After the initial experimental matrix was completed, several single-variable experiments were run to fine tune the recipe. Based on the data analysis and the model results from the design of experiment, two optimal C/sub 4/F/sub 8/ cleaning processes were identified. Both processes significantly lowered gas consumption and PFC emissions. Marathon process testing showed no adverse impact on film properties or device yield.
Garnitures mécaniques d'étanchéité
Keywords: etancheite ; mecanique Reference Record created on 2005-11-18, modified on 2016-08-08