This book has suggested methods to begin to analyze the plasmas used for processing semiconductors, as well as the neutral chemistry used with the plasma, and the reactors used to create and contain the plasma. The material in this book should provide a solid base for understanding current research issues in this field and access to the relevant literature. To conclude this work, the appropriate way to describe these plasma systems will be considered, with emphasis on the tools needed to fully understand the plasma and to design a reactor.

Unlike most textbooks, there was no suggestion that we were giving a complete treatment of the problem. When textbooks give this impression, it is almost always misleading. This is particularly unfortunate, because it tends to discourage the reader from thinking creatively and independently about real problems, which cannot be handled in an oversimplified way.

To the extent that it is possible to formulate a general strategy for handling complex problems (such as processing plasmas), the strategy suggested is: Use the known experimental results and physical knowledge to set up simple models. Test the models by means of experiments. Refine the models and test them again. Repeat as often as necessary/possible.

It might seem that this process is the “hypothesis testing” that is supposed by philosophers of science to take place in all scientific endeavors. It is not the same, however. The sort of hypothesis they usually envisage is a single, straightforward idea.