Semiconductor work was very 'kewl'! I was a maintenance tech on the machines used to manufacture chips. Worked in Diffusion (big hot furnaces), and Ion Implant (big machines that used VERY high voltage levels,and huge magnets). Both areas used dangerous gases. Implant was probably neater from a scientific perspective. Ionizing the gas, extracting the ions, and then 'shooting' them into the silicon wafer surface in a very controlled fashion.

It was quite fun to work on those machines. Even if we had to worry about ionizing radiation and arsenic exposure. One of the gases was a hydride of arsenic. Did ya know that arsenic smells like garlic?