They aren't built at the same scale, they're much larger than the final structure and lenses are used to scale the image down to the desired size.

Here's a video form Intel on how they are made: https://youtu.be/u3ws0UebnSE

Apparently they use "electron beams", not sure what those are, they sound similar to lasers but with electrons, from this video: https://youtu.be/PWV9pvdRBNY

Wow, this explains why production of a mask takes 5 days (as said in first video):

https://en.wikipedia.org/wiki/Electron-beam_lithography

Wouldn't that just be something like CRT? https://en.wikipedia.org/wiki/Cathode-ray_tube

It's probably closer to how an electron microscope works.

This was also a cool video I saw recently about lithography with plasma lasers https://www.youtube.com/watch?v=f0gMdGrVteI around 7:14 in particular

Photographic reduction. The masks are much larger than the final chips. https://commons.wikimedia.org/wiki/File:Semiconductor_photom... (Actually AIUI in EUV photolithography you can't use transparent masks, but must use a kind of mirror with the pattern etched onto it.)

According to Wikipedia masks are only 4 times larger - it is still very tiny.

Lenses are used so the feature size on the mask is larger than the feature size on the wafer.

https://www.nikon.com/about/technology/product/semiconductor...

Yes, but only few times. Still not clear how an initial mask has been produced? From file to mask - a kind of printer or a laser?

for >1 micron it's optical lithographic transfer, for <1 micron, it's e-beam lithography.