generate fill dummy metal

Hi everybody,

The question is: someone can tell me how generate the fill dummy metal and how to set the rules in ASSURA? Are there some tutorial available?

There are some old threads but really nobody answered how to do it.

We want control the potential parasitics and do not let the generation to the foundry.

Thanks in advance,
Best regards

Hello The rules file should have been supplied with the pdk kit, usually the fill program outputs a gds file which can be streamed in and placed on the top level. Be careful using fill scripts blindly as they can increase the chance of crosstalk.

We always had some CAD dude write scripts in-house.
We (I always worked inside semiconductor foundries)
did not let customers do the fills.

However you might try the foundry's tape-in procedure
("mock tape-in") as a way to get a filled "blow-back"
database which you could then pick at in places where
you think parasitics matter.

Alternatively you could look in the PDK for cells that
look like pattern fill unit cells and go at it yourself, or
create one of your own (they tend to be simple, like
criss-crossed interconnect and contact layers at min
space, maybe with a border polygon for convenience).
When I did my own fills I distrusted the scripts and
did it by hand, using arrayed instances of the fill cell
provided. I often thought about how nice it would be
if, say, a pattern fill was also a useful on chip decoupling
capacitor. And I often made these and used them under
bussing to drive the density up, requiring less "dummy"
fills to meet rules.