Smaller geometry and larger wafer size are the major trends for today's semiconductor device manufacturing industry in order to attain higher throughput and better device performance. At the same time, tool uptime and process yield become more important as they are closely related to the fab throughput. Significant efforts have been spent on improving the process throughput by employing advanced tools, new process chemistries and more efficient in-situ cleaning steps. However, it was found that the tool usage is often reduced because of existing downstream problems. In addition, particle levels on wafer surface are also related to the cleanness of the pump line. These problems are even getting worse because of the use of more reactive precursors, which are intended to reduce the process temperature and increase the deposition rate. The most common processes which are experiencing significant downstream problems are silicon nitride LPCVD, TEOS LPCVD, Aluminum etch, tungsten CVD process, silicon Epi, and variety of other processes. These problems can be caused by physical sublimation of the condensable by-products, or the complex chemical reactions between unreacted precursors, by-products, and/or the vapor backstreaming from the scrubber. Different techniques are required to manage these effluent problems because of their different mechanism. In addition, a systematic solution is often required in order to prevent creating a problem. Several downstream effluent management subsystems developed at MKS Instruments Inc. will be discussed in this talk. They have been proven very effective to improve semiconductor manufacturing process uptime and yield.