Silicon wafers are circular [because] “Nature wants to build them round”.

And not because the vat from which the crystal is pulled is most easily made with a circular cross-section?

“Processor wafers are made out of silicon, or more precisely melted sand”

LOL
What were you thinking.
Sand (impure SiO2) is not Silicon (unbelievably pure Si)

As to why it is round. The ingot is rotated as it is pulled

Where do they get the sand from?

Czochralski died in 1953. The Lod airport massacre happened in 1972. Not sure what you were trying to do there with that wild statement.

I saw a ‘Texas Instruments’ ingot being pulled out of the bath on ‘How it’s Made’ the other day. The pure ‘log’ of silicon is an awesomely beautiful object.

I would guess it is because the crystal-growing process naturally produces a sausage-shaped (but much larger, nowadays) crystal, which is then sliced into wafers. Another factor might be that the processing chambers work better when they are round so there are no corners for the circulating gasses, etc.

in a sense they are created from sand, the sand is cooked in reactors with different gases where the end product is a very pure product called “poly silicon”
It then gets melted down inside a crystal growing furnace, not in a vat, in a quartz crucible (bowl)

turning the ingot into wafers is a multistage process, and the wafers are often spun rapidly to etch/clean them. Round wafers go better at 2000rpm + than square wafers