What materials and devices require manufacturing in a vacuum environment?

[aquitaine]

I heard somewhere that some materials and devices need to be manufactured in a vacuum environment. I heard superconductors was one of them, but I'm wondering what else there is?

 

[Mapes]

Many integrated circuit (IC) and microelectromechanical systems (MEMS) manufacturing steps use a near-vacuum. It's convenient to have no air in the way if you want to transfer material from a source to the IC silicon wafer (e.g., sputtering, evaporation). A near-vacuum also makes it possible to strike an electrical plasma, which can drive certain desirable chemical reactions (e.g., plasma ashing, reactive ion etching).

 

[Astronuc]

Melting (for ingot production) of refractory alloys is done in a vacuum, as well as vacuum casting, and electron beam welding.

For refractory alloys like those of Zr, Ti, and others cannot be fabricated in air because they absorb oxygen and nitrogen, which can have a deleterious effect on corrosion and mechanical behavior. In addition, hydrogen cannot be present.

 

[aquitaine]

So it sounds like quite a few applications require it. Interesting.