4 ms·

> 65nm? 90nm? 180nm? I'd argue that the processes can be improved and cost can probably come down compared to the older machines. This is really dubious for tw

> 65nm? 90nm? 180nm? I'd argue that the processes can be improved and cost can probably come down compared to the older machines. This is really dubious for two reasons. First, you can do a die shrink and fit many, many more equivalent chips onto a single wafer at a modern node. This is somewhat mitigated by the high cost of mask sets at modern nodes -- but there's just no way it would ever make economic sense to build capacity at 180nm. Second, the equipment for old nodes is not made anymore. It's cheap, but that's only because there's ample supply on the secondary market. If fabs began to get restarted in earnest at old nodes, that supply would quickly evaporate. Then you would have to buy modern (expensive!) equipment -- at which point why not take advantage of its full potential? Wafer throughput is the same regardless of whether you're making 100 chips per wafer at 180nm or 10,000 at 22nm.

baybal2 5y ago
Do you know how much modern masksets cost? More than a MILLION DOLLARS for a set, and completely ridiculous sums for anything <28nm. So, if your market is <1M dies a year, you have to price your chip >$1 just to break even. And in the car chip market, even 1M dies is a giant amount. Car market was all about decades old chips, made to stringent automotive specs, manufactured in tiny batches, and sold on long term contracts at sub-10 cent per packaged, tested, and binned die (and low bin chips were usually simply thrown away.)
- nwiswell 5y ago
  > So, if your market is <1M dies a year, you have to price your chip >$1 just to break even. And in the car chip market, even 1M dies is a giant amount. No, this is not the case. If you have a small run, the foundry will "consolidate" your chip with other customers to make a single mask. This makes sense all around, since the foundry would rather not have to deal with a mask set that has only a few wafer starts anyway.
  - baybal2 5y ago
    You don't make commercial chips on a shuttle run. If you sit on the same mask as somebody else, you forsake all the flexibility, and you are limited to fabs with own mask shops — just taking your masks, and moving to another fab with them is near impossible. Asking the fab to make just any process tweaks is similarly impossible.
    - deleted 5y ago
      [deleted]
    - nwiswell 5y ago
      I've never heard of a customer getting process tweaks for a one million die run, but then again I've got no experience with legacy fabs. Certainly the 14nm fab that Intel promised lately[1] for automotive demand would not entertain that sort of thing. [1] https://www.electronicdesign.com/markets/automotive/article/21174750/electronic-design-intel-to-commit-foundry-capacity-for-chipstarved-auto-industry https://www.electronicdesign.com/markets/automotive/article/...
raverbashing 5y ago
> buy modern (expensive!) equipment -- at which point why not take advantage of its full potential? Wafer throughput is the same regardless of whether you're making 100 chips per wafer at 180nm or 10,000 at 22nm Yes, I agree, but what I'm saying is that there's a cost optimum that might not necessarily be at 22nm (you get more chips per wafer but if the machines cost 10x as much, let's say, then it's not necessarily worth it) I'm not even sure everything can be shrunk that easily. Power ICs for example.
- nwiswell 5y ago
  > you get more chips per wafer but if the machines cost 10x as much, let's say, then it's not necessarily worth it That's sort of the point I'm making here: there is fundamentally no real cost differential unless you go really far back to when the equipment was really rudimentary. The old machines are cheap because they're used. If there was someone still manufacturing them, their cost would not be greatly different from modern equipment. The best analogy I can make is an old car. Being older doesn't mean it's a whole lot cheaper to manufacture. Maybe a little -- no fancy computers or direct fuel injection -- but you lose that benefit really fast because of the shitty fuel economy. Most of the modern equipment is "backward compatible"; modern CVD or PVD or CMP or etch equipment would work fine at any trailing node, with the exception of the fact that they would work only with 300mm wafers (which is actually an added cost efficiency). The biggest difference I could imagine is with litho equipment. 193nm immersion is expensive and EUV is even more outrageous. You could probably use old non-immersion litho technology with modern multiple patterning instead.
  - buescher 5y ago
    Apologies for arguing the analogy, but the Benjamin Button car buyer would lose horsepower and weight (=safety and convenience features) to continue to make mandated fuel economy standards. You could buy a 50 mpg CRX HF from Honda over 30 years ago, but you'd probably be very unhappy with its performance today. Small relative increases in fuel economy don't save you that much money, either

baybal2 5y ago

Do you know how much modern masksets cost? More than a MILLION DOLLARS for a set, and completely ridiculous sums for anything <28nm. So, if your market is <1M dies a year, you have to price your chip >$1 just to break even. And in the car chip market, even 1M dies is a giant amount. Car market was all about decades old chips, made to stringent automotive specs, manufactured in tiny batches, and sold on long term contracts at sub-10 cent per packaged, tested, and binned die (and low bin chips were usually simply thrown away.)

nwiswell 5y ago
> So, if your market is <1M dies a year, you have to price your chip >$1 just to break even. And in the car chip market, even 1M dies is a giant amount. No, this is not the case. If you have a small run, the foundry will "consolidate" your chip with other customers to make a single mask. This makes sense all around, since the foundry would rather not have to deal with a mask set that has only a few wafer starts anyway.
- baybal2 5y ago
  You don't make commercial chips on a shuttle run. If you sit on the same mask as somebody else, you forsake all the flexibility, and you are limited to fabs with own mask shops — just taking your masks, and moving to another fab with them is near impossible. Asking the fab to make just any process tweaks is similarly impossible.
  - deleted 5y ago
    [deleted]
  - nwiswell 5y ago
    I've never heard of a customer getting process tweaks for a one million die run, but then again I've got no experience with legacy fabs. Certainly the 14nm fab that Intel promised lately[1] for automotive demand would not entertain that sort of thing. [1] https://www.electronicdesign.com/markets/automotive/article/21174750/electronic-design-intel-to-commit-foundry-capacity-for-chipstarved-auto-industry https://www.electronicdesign.com/markets/automotive/article/...

raverbashing 5y ago

> buy modern (expensive!) equipment -- at which point why not take advantage of its full potential? Wafer throughput is the same regardless of whether you're making 100 chips per wafer at 180nm or 10,000 at 22nm Yes, I agree, but what I'm saying is that there's a cost optimum that might not necessarily be at 22nm (you get more chips per wafer but if the machines cost 10x as much, let's say, then it's not necessarily worth it) I'm not even sure everything can be shrunk that easily. Power ICs for example.

nwiswell 5y ago
> you get more chips per wafer but if the machines cost 10x as much, let's say, then it's not necessarily worth it That's sort of the point I'm making here: there is fundamentally no real cost differential unless you go really far back to when the equipment was really rudimentary. The old machines are cheap because they're used. If there was someone still manufacturing them, their cost would not be greatly different from modern equipment. The best analogy I can make is an old car. Being older doesn't mean it's a whole lot cheaper to manufacture. Maybe a little -- no fancy computers or direct fuel injection -- but you lose that benefit really fast because of the shitty fuel economy. Most of the modern equipment is "backward compatible"; modern CVD or PVD or CMP or etch equipment would work fine at any trailing node, with the exception of the fact that they would work only with 300mm wafers (which is actually an added cost efficiency). The biggest difference I could imagine is with litho equipment. 193nm immersion is expensive and EUV is even more outrageous. You could probably use old non-immersion litho technology with modern multiple patterning instead.
- buescher 5y ago
  Apologies for arguing the analogy, but the Benjamin Button car buyer would lose horsepower and weight (=safety and convenience features) to continue to make mandated fuel economy standards. You could buy a 50 mpg CRX HF from Honda over 30 years ago, but you'd probably be very unhappy with its performance today. Small relative increases in fuel economy don't save you that much money, either