My ex is a process improvement engineer at Intel she told me a story about considerably higher failure rate for silicon that was manufactured in a northern part of a room vs the southern part what’s more odd is that it only affected some products that shared this room in their pipeline.

The cause was that the water pipes under that section would impact that part of the process because of mechanical vibration the reason why it didn’t impact all processes because they were tied to the cooling system and it only had an effect when other procsses put stress on it.

These vibaration were apparently so small that they couldn’t measure the difference they identified this through a process of elimination.

This is a classical story of practical vs theoretical engineering the secret sauce isn’t the recepie it’s the cook.

If you think about it this way if it was so easy to recreate a process through reverse engineering a few hot chips talks and poaching Intel wouldn’t be in this mess and GloFo didn’t had to scrap their 20nm process.

When you almost at the level of moving atoms around the wing flaps of a butterfly start to really matter.

We’re well pass the time where you had Disney animators draw transistors on sheets and copper masks were cut by hand it wouldn’t surprise me if there are no beans days at foundries these days since a fart across the building might increase your defect rate by 3%