This is an image of a die that was given
a bevel polish, so that we can look at the transistors in plan view:
On another part of the bevel we can see
the fins, and here we have counted 20 pitches:
Which agrees with the 42-nm pitch in the
Intel webcast. So far, so good!
If we look at the cross-section, Intel
has stayed with their thick top metal that they have been using since the 65-nm
node, which means that we have to squint awfully hard to see THIRTEEN layers of
metal, and a MIM-cap layer under the top metal.
A
look at the edge seal, which doesn’t have the top metal or the MIM-cap, makes
it easier to count twelve layers:
We are used to seeing twelve-plus metal
layers in IBM chips (their 22-nm Power8 has fifteen!), but Intel has been using
nine for the last few generations, going up to eleven in the Baytrail SoC chip.
Intel quoted 52 nm interconnect pitch,
but we see 54 nm:
The cross-section seems to show that
essentially the 14-nm process is a shrink of the 22-nm technology, with the modified
fins; the gate metallisation looks similar to the 22-nm, with tungsten gate
fill as in the earlier process. (As an aside, this will make it the fourth
generation replacement metal gate process – this technology has legs!)
Intel
and IBM are giving late news papers at IEDM in December, and apparently there
are air gaps in the back-end dielectric stack – we have not found those yet. We
have confirmed the SRAM cell size in the cache memory is ~0.058 sq. µm.
Our analysis is ongoing, and we look
forward to some great images! And as always, we will be doing a bunch of reports..
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