[dsr3]

Some people said because Arizona is in relatively stable seismic region in the US. But I don't buy it. TSMC fab in Taiwan is also located in seismic prone region. Compared to the cost of the fab itself, seismic isolation system is relatively affordable.

[akiselev]

They need seismic isolation regardless of where they build. Cutting edge fabs require such precision that a poorly shielded USB port can cause enough noise to create problems, let alone the vibrations from distant earthquakes. (Source: previous work with electron microscopes)

Fabs are expensive because every part of building it from the electrical wiring to the seismic isolation to the HVAC system needs to be perfectly tuned to remove all sources of noise. Most of these costs are superlinear if not exponential with the magnitude of noise.

[dharbin]

I heard a story about an Intel fab in Arizona that would always produce bad silicon at a certain time a day. After some investigations it was determined that a train passed by at that time every day causing enough seismic activity to disrupt the manufacturing process.

[foobiekr]

Logistics risks around the plant are not nearly as easily done. There is an inherent benefit to not being exposed to seismic and weather issues. AZ isn’t a bad choice.