This technical note addresses the problem of particle contamination caused by vacuum pump failures in semiconductor process equipment, particularly in etch or deposition tools that deal with abrasive and/or corrosive exhaust gases. Vacuum pump failures produce turbulence and back-streaming in the foreline and process chamber, dislodging particles from the foreline walls and contaminating wafer surfaces.
The app note provides background information on vacuum systems, including the design of vacuum pump systems, and the isolation valves used in semiconductor process tools. The note highlights the importance of the closing time for isolation valves to prevent contamination, which is a critical performance specification. The app note provides recommendations to reduce the chance of particle migration into the process chamber when a pump failure occurs.
