TSMC 4nm node is a quarter ahead of schedule

TechPowerUp noticed TSMC's 4nm process seems to be doing better than expected. Previously, the Taiwanese foundry expected to start test production in Q4 2021, but this has now moved to Q3 2021. N4 is a further optimization of the N5 process node.

This could mean an equivalent - or perhaps even better - reduction in volume production and time-to-market, but it's anyone's guess at this point. As notably difficult and onerous as semiconductor development is, problems are more likely to appear than not. 4 nm is expected to bring respectable improvements to the PPA equation for semiconductors over 5 nm - however, TSMC still hasn't disclosed expected gains.

Why foundries are building fabs in dry Arizona

In related news, ARS Technica has an interesting article about why chip makers keep building fabs in Arizona. Both TSMC and Intel are constructing new production capacity in Arizona, one of the driest nations in the United States. According to Forrester research director Glenn O'Donnell, a chip fab is a lot like an indoor swimming pool. You need a lot of water to get it started, but you don't have to add much to keep it going. The site highlights that while semiconductor factories need a lot of water, this is not an important factor versus the benefits Arizona has to offer.

What Arizona lacks in water, it makes up for with overall stability—the state is very seismically stable and does not suffer from hurricanes or wildfires, with low risks of other natural disasters such as tornadoes to boot. Building chip fabs without such guarantees is possible—for example, Intel has a large presence in Oregon—but chip fabricators on the West Coast must take extreme isolation measures, which Arizona plants don't require.

Other than this, the state also has a strong reputation for semiconductor design courses and research, partly thanks to Intel's +40 year presence in the state.