The 30% ruling isn't specific to ASML, it's a general tax credit you get if you're a non-EU national that moves to the Netherlands (plus a bunch of other conditions) on a sponsored work visa.

https://business.gov.nl/running-your-business/staff/terms-of...

Whether ASML and their employees get extra benefits on top of the 30% ruling I'm not sure, I wouldn't be surprised if they do though.