>Because even the smallest vibration could cause a chip to be damaged - so small and precise are the movements of the lithography machines on the floor above.
Why is the Newport factory so valuable?
>That brings us back to the key thing you need to know about these places.
>One of the most important marks of a good chipmaker is not merely the clever IP they have in-house, but their ability to make working chips consistently.
>That might sound like a statement of the bleeding obvious, but it really matters.
>All silicon chips begin their lives as a large circular slice of pure metallic silicon - a "wafer".
>These wafers are expensive, and even more expensive are the machines in which they sit and whizz around - a process which takes months - as the transistors are etched into them.
>Eventually, at the end of the process here in Newport, the wafers are imprinted with many hundreds of little squares, each of which will be sliced off the wafer and will later become a silicon chip.
>But these wafers rarely yield chips that all work; sometimes a fleck of stray dust will land in the wrong place, maybe there was an unexpected vibration or some light damage (hence why the fab is bathed in yellow light that is less likely to affect the silicon).
>At least a few chips on each wafer are unlikely to pass quality control.
>So, a mark of a fab's success is its average yield, and it turns out on this front Newport is very good indeed.
>With a yield percentage in the very high 90s, among power silicon chipmakers it's one of the best in the world.
>The other thing that's under-appreciated is how valuable this site is.
>If you wanted to tear down this building and reconstruct it, with all the machinery, it would probably set you back about a billion pounds.
>It is, in other words, one of the most expensive factories in the UK.