5 ms·

Isn't that survivorship bias? Processes that never improve yield are abandoned

kragen 3y ago
no, it's just what happens with any process; as you gain more experience with it, you learn more about it, so you can get more and more controlled results
- gary_0 3y ago
  Yes, and companies like TSMC and Intel probably have vast internal documentation about where and how their processes can improve yield as they run their newest fabs. The research required to implement a new process can take decades to get to the mass-production stage. Given the billion of dollars at stake and thousands of human-years of R&D needed, none of these companies are "winging it" and their scientists and engineers know how to plan ahead to the best of their considerable abilities. For a glimpse at how they do things, see this fascinating talk: https://www.youtube.com/watch?v=NGFhc8R_uO4 https://www.youtube.com/watch?v=NGFhc8R_uO4
  - shard 3y ago
    > Given the billion of dollars at stake and thousands of human-years of R&D needed, none of these companies are "winging it" You'd be surprised. My personal knowledge of one major fab is that they have policies such as regular rotation of employees which make it difficult to maintain institutional knowledge. I have heard complaints from multiple people of their teammates and managers "winging it" to think it's isolated incidents.
    - gary_0 3y ago
      Cynical thoughts along these lines occurred to me after I posted my comment, so no, I'm not surprised, just disappointed. Especially not after watching Intel slowly rot from the inside (good luck with your renovations, Mr. Gelsinger). My workmate at my last job (pre-COVID) knew someone who worked at Intel, and our discussions about the company tended to contain the phrase "Intel is fucked" an awful lot. This was around the time I bought a nice chunk of TSMC stock...
gary_0 3y ago
Historically, maybe, but otherwise that's not how it works. Nowadays, when a new process enters risk production, yields are expected to be sub-optimal (I think I read that some of the recent stuff TSMC was making for Apple was below 50%) but it's an economic imperative that they improve (and they do). Abandoning a process once you've built an assembly line would be an existential crisis for a high-end semiconductor company, given the billions of dollars it costs to get to that point (which is a big reason why Intel has been between a rock and a hard place for the past 5 years or so).

no, it's just what happens with any process; as you gain more experience with it, you learn more about it, so you can get more and more controlled results

gary_0 3y ago
Yes, and companies like TSMC and Intel probably have vast internal documentation about where and how their processes can improve yield as they run their newest fabs. The research required to implement a new process can take decades to get to the mass-production stage. Given the billion of dollars at stake and thousands of human-years of R&D needed, none of these companies are "winging it" and their scientists and engineers know how to plan ahead to the best of their considerable abilities. For a glimpse at how they do things, see this fascinating talk: https://www.youtube.com/watch?v=NGFhc8R_uO4 https://www.youtube.com/watch?v=NGFhc8R_uO4
- shard 3y ago
  > Given the billion of dollars at stake and thousands of human-years of R&D needed, none of these companies are "winging it" You'd be surprised. My personal knowledge of one major fab is that they have policies such as regular rotation of employees which make it difficult to maintain institutional knowledge. I have heard complaints from multiple people of their teammates and managers "winging it" to think it's isolated incidents.
  - gary_0 3y ago
    Cynical thoughts along these lines occurred to me after I posted my comment, so no, I'm not surprised, just disappointed. Especially not after watching Intel slowly rot from the inside (good luck with your renovations, Mr. Gelsinger). My workmate at my last job (pre-COVID) knew someone who worked at Intel, and our discussions about the company tended to contain the phrase "Intel is fucked" an awful lot. This was around the time I bought a nice chunk of TSMC stock...

gary_0 3y ago

Historically, maybe, but otherwise that's not how it works. Nowadays, when a new process enters risk production, yields are expected to be sub-optimal (I think I read that some of the recent stuff TSMC was making for Apple was below 50%) but it's an economic imperative that they improve (and they do). Abandoning a process once you've built an assembly line would be an existential crisis for a high-end semiconductor company, given the billions of dollars it costs to get to that point (which is a big reason why Intel has been between a rock and a hard place for the past 5 years or so).