[krazerlasers]

Somewhat counterintuitively, the primary gas species used in excimer lasers are noble gasses. A typical gas mix for a 193nm excimer laser would be ~97% neon and just a few percent of the actual argon/fluorine excimer mix. [1]

Since you mentioned them -- as hard as it may be to believe -- HeNe lasers are only just beginning to be phased out in the semi industry in the somewhat esoteric use case of precision position measurement using interferometry. The output wavelength of a HeNe lase is extremely stable--with a simple feedback loop on the cavity length (ie, temperature) a HeNe laser is essentially an atomic clock locked to the 473.612248 THz 5s2 → 3p HeNe line. Interferometers built around such systems can accurately measure sub-nanometer displacements and are able to achieve a lifetime absolute stability of better than 10ppb--comparable to a rubidium atomic clock! [2]

[1] https://www.linde-gas.com/en/images/Gasworld%20Excimer%20Las...

[2] https://www.repairfaq.org/sam/laserhst.htm#hstish3