Beamer - Re: ", but I've been under the impression that extra metal layers are a liability, rather than an asset. AMD's .13u process has 9 copper layers. While you are correct that this will make routing easier and more compact, it will also mean more steps in manufacturing, which mean longer turn-around times, and more $$$. I just don't know whether the pros outweigh the cons"
You have identified the trade-offs - smaller die sizes vs added manufacturing complexity and cost.
With 1 extra metal layer, I'd guess their are 3 extra mask steps out of about 25 or so mask steps.
Roughly, that will cost an extra 3/25 or 12%.
If the die size can be reduced by at LEAST 12%, it is a wash.
For die size reduction >12%, the smaller die size wins, assuming no loss in yields.
For Intel, this is a GOOD trade off - for AMD, with their poor 34% yields at 6 metal layers, adding 3 more layers is going to be a nightmare.
Paul |
