Manual metal fill to meet local metal density problem, possible?

[flwong]

Dear friends, I am working in RF circuit design project using 65nm tech. There is strict requirement on local metal density. Auto-fill utility can help but greatly affect circuit performance. Manual dummy metal fill is used but it seems not very useful.

Any suggestion?

 

[erikl]

It's Hobson's choice - and the Fab's appreciation.

 

[johnjoe]

Ahh, second post of you, ok maybe I should ask again here: Why the manual metal fill is not useful for you and what exactly is affected by the automatic metal fill? Give us some more informations.

 

[Catalin_C]

Hi there,

In my opinion, the manual metal filling is highly recommended if you have critical mathing areas, make sure you fill simmetrical and exclude that area from automatic metal fill.
If the critical area is very small you can simply exclude it from automatic fill and not place any manual fill also, but if the area is larger proceed as I mentioned above.
Dont connect the metal fill to anything! and keep the metal in small size.