A Vision for IC DFM
Many EDA startups got funded in the last 3 years to address
Design For Manufacturability of Chips. Catena, however, was an
internal Cadence project that finally sees light of day.
Catena does post-layout optimization on shape-based parameters
(vias, wires) to arrive at a better interconnect design, before
handing off to the Fab or the Foundry.
As chips gets denser and denser, the pressure on layout engines
intensifies, to accomodate all this functionality within a tiny
perimeter. The victim, naturally, is yield.
Hence, the chip industry has been looking for ways to handle
yield issues at the design stage.
This step is one in the right direction.
However, it is still a long way from being able to do predictive
modeling using parameters of the manufacturing process before
and during layout. Setting constraints and catching violations
or risks pre- and during layout are still more valuable than
correcting things after, as the degrees of freedom tend to go
down dramatically as the process progresses.
Catena, therefore, is only a tiny step in the direction of a
massive and ambitious vision that many in the industry harbor.
My articulation of this vision is as follows: An exhaustive
Design Rule Checker (DRC) that contains in its heart an Expert
System that understands the manufacturing Process and
Equipments, Properties of Materials, Temperatures, Signal
Integrity, Power and Voltage issues, etc. This uber-DRC will
then run through its rule-base - every Layout decision, make
estimates about downstream Layout options/decisions (like a
Chess Player), and help along the Layout optimization process.
And a lot more!