Teaching vacuum technology using spreadsheet calculations

Vacuum technology is an important part of nano-fabrication. Automated control systems for vacuum equipment have made operation easy and safe but have also isolated the user from the need to understand the physics of vacuum systems. In spite of this, many equipment and process decisions revolve around choices made concerning the vacuum components of a processing tool. Students can use a spreadsheet to calculate the pump down pressure characteristic in a chamber for various non ideal conditions and combinations of single and multiple stage pumps. The calculations can be compared to characteristics of real pump/chamber systems that are available in the user's laboratory. This develops a much deeper understanding of the design and operation of modern vacuum systems. The calculations are also a good way to introduce or review numerical techniques.