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Can someone explain why neon is critical for "lasers used in chip manufacturing" ? I don't think they'd be using He-Ne lasers, and if they are I would think th

Can someone explain why neon is critical for "lasers used in chip manufacturing" ? I don't think they'd be using He-Ne lasers, and if they are I would think those could be replaced fairly easily with solid-state lasers.

perihelions 5y ago
Deep-ultraviolet excimer lasers, I think (?). Not a domain expert! - "Excimer laser gas mixtures are a combination of rare gases (argon, krypton, xenon, or neon) and halogen gases (fluorine or chlorine). The mixture of gases determines the wavelength of DUV light produced. Argon+fluorine+neon (193nm) and Krypton+fluorine+neon (248nm) are the two most common mixtures used. In terms of volume; neon makes up approximately 96–97.5% of the mixture." https://www.linde-gas.com/en/images/Gasworld%20Excimer%20Laser%20Gases%20May%202017_tcm17-419058.pdf https://www.linde-gas.com/en/images/Gasworld%20Excimer%20Las...
jbay808 5y ago
There could very well be HeNe lasers used as an interferometric length standard in lithography equipment. There are some solid-state lasers that could substitute for that role, such as NPRO lasers, but they're much more expensive and not widely produced.
krazerlasers 5y ago
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%20Laser%20Gases%20May%202017_tcm17-419058.pdf https://www.linde-gas.com/en/images/Gasworld%20Excimer%20Las... [2] https://www.repairfaq.org/sam/laserhst.htm#hstish3 https://www.repairfaq.org/sam/laserhst.htm#hstish3

perihelions 5y ago

Deep-ultraviolet excimer lasers, I think (?). Not a domain expert! - "Excimer laser gas mixtures are a combination of rare gases (argon, krypton, xenon, or neon) and halogen gases (fluorine or chlorine). The mixture of gases determines the wavelength of DUV light produced. Argon+fluorine+neon (193nm) and Krypton+fluorine+neon (248nm) are the two most common mixtures used. In terms of volume; neon makes up approximately 96–97.5% of the mixture." https://www.linde-gas.com/en/images/Gasworld%20Excimer%20Laser%20Gases%20May%202017_tcm17-419058.pdf https://www.linde-gas.com/en/images/Gasworld%20Excimer%20Las...

jbay808 5y ago

There could very well be HeNe lasers used as an interferometric length standard in lithography equipment. There are some solid-state lasers that could substitute for that role, such as NPRO lasers, but they're much more expensive and not widely produced.

krazerlasers 5y ago

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%20Laser%20Gases%20May%202017_tcm17-419058.pdf https://www.linde-gas.com/en/images/Gasworld%20Excimer%20Las... [2] https://www.repairfaq.org/sam/laserhst.htm#hstish3 https://www.repairfaq.org/sam/laserhst.htm#hstish3