I greatly enjoyed the opportunity to get some hands-on experience in a semiconductor foundry and learning about the complex and varied processes involved in the manufacturing of CMOS logic. Besides spending a lot of time in the clean room environment, it was interesting to see other aspects of factory operation, which was possible through facility tours and time spent with some of the engineers.
I had opportunities to learn about and implement the design of experiments methodology, and to work with large amounts of tool data and perform analyses. These topics are not covered explicitly in my coursework at school, but they are valuable skills!
What I wish was different
Advice
Make the most of time spent with the engineers! Come up with questions, and review relevant background material. They are usually rather busy with other obligations, so don't waste their time (or your own!)