No but they’ll happen in an inert atmosphere, not sure about plasma etching that may require a vacuum chamber similarly to sputtering. The only steps that abso

No but they’ll happen in an inert atmosphere, not sure about plasma etching that may require a vacuum chamber similarly to sputtering. The only steps that absolutely require vacuum are sputtering and ion deposition (doping), depending on the wavelength used vacuum may be used/required for the lithographic exposure too but I’m not sure if it’s actually needed especially since some lithography requires submersion. That said nothing will be done under normal atmospheric conditions, even the oxide layer will be controlled with specific oxygen rates.