Arizona has access to a lot of the larger rivers like the Colorado, so they can get water pretty easily, and then at least when I was in Arizona, I knew a business owner from China who opened their company there because of the relatively low tax rates. But they're not super low from what I remember. Let me check. Yeah combined corporate tax rate of over 9%, which is apparently the 19th of the US for corporate tax rates.

Water access is there, there's obviously tons of super cheap land for development, and the corporate tax rates aren't so bad.

Oh, and it looks like they have low seismic activity, which is important for such delicate precise manufacturing.

Arizona is trying to make itself the semiconductor center of the US.

Here are their own stated advantages: https://www.azcommerce.com/industries/manufacturing/semiconductor-advantages/