OK. But maybe plastic bags and tanks of helium?
These events have been shown to be very rare, and the costs would greatly outweigh the benefits (for the time being).
The cheapest piece of equipment was the stand the FOUPS come down and rest on. From memory, that was easily 5 figures, perhaps low 6. Every other piece of processing equipment was insanely more expensive.
Queuing theory is an active field of research with great applications in how wafer processing. The total process has to be looked at. Wafer priority, wafer value, planning preventative maintenance on the machines, etc. could all be taken into consideration when scheduling when wafers will run.
Retrofitting every "robot" that grabs FOUPS for a much heavier load, upgrading the tracks if needed, replacing every single FOUP, adjusting factory flow and inventory holding areas, doing qualifying trials on the FOUPS (to make sure they're functioning correctly and not leaking), etc. are considerable expense.
Prioritization of wafers and timing the preceding step so the required machine is certain to be ready in the window would yield better results from a strict business ROI perspective.
What does that mean? Is 'yield' not the end usable product from the batch?
It's a familiar concept from organic chemistry.
Edit: If yield per step averages 99.8%, and there are 500 steps, overall yield is 36.8%.
At the same time, when wafers get scrapped, they do justify why they were scrapped. There are metrology processes and tests performed as you go to ensure you don't run ruined wafers through additional manufacturing steps.
The gist of that part is meant to show how important and impressive the entire process is. In "normal" manufacturing, 99.8% good parts is a pretty darn good process. Many of the easy wins are already implemented. Most normal things are manufactured in far fewer steps, so even if you're only making 95% good parts, it doesn't absolutely kill your total recovery (start to finish).
Yes. And I was responding to georgeburdell's comment about long-term losses from this virus infection. In that maybe some crude hack could ameliorate them.
> For those of you thinking that TSMC only gets set back by the time it took to recover the equipment from the virus (1-2 days), realize that there are some critical steps in the manufacturing process that require completion within X time or the wafer is trash. Also realize that wafers take several weeks of fab processing, and this may be a substantial hit to their output for a while.
Everything in semiconductor is basically incomprehensible in scale. A scanner (i.e., the photo lithography projection tool) takes about 2 seconds to fully expose a wafer. that wafer probably has 100 individual chips on it each of which have around 2 billion transistors. That means that tool is helping create 100 billion transistors a second.
The great grand parent comment is right...but the lose of that is probably on the range of one-two weeks production. retrofitting the fab like you suggest, and to be clear it isn't a fundamentally bad idea, would cost billions and take months if not years. What you propose is technically correct but business irrelevant.
Long term here means a week or so...it's expensive but rare. They don't play with 'crude hacks' because you don't know the implications of that hack 10 years from now when the chip is running part of the stock market.
It's just an industry that is hard to process, whether you work in it or not, because of the scale and the precision.
In school (industrial engineering) we talked about length and thickness tolerances being quite tight at 1/10,000 inch. The units used in semiconductors are nanometers, angstroms, etc. You might do a process and lay down just a couple atom thick layer of material...I had no idea that was physically possible.
Semiconductors still blow me mind...eventually we will run out of base silicon to use and are possibly really fucked but its been a fun ride so far.
No, thats not real, that's a silly science fiction novel.