Why do we insert antenna fillers into a chip?

[sharas]

Hi,

Why do we insert antenna fillers into the chip? I'm talking about cells that are left unconnected, not cells that are inserted to fix specific antenna violations that are reported by the tools (Magma, Calibre etc.)?

Thanks,

Sharas

 

[vikramc98406]

Re: Antenna fillers

I don't think there are any specific Antenna Fillers placed.
Once we complete the place, route, time the design and verify the design, the left over place will be filled with dummy cells called filler cells which are not used any where.

The usage of these fillers is to maintain continuation of active regions.
Also can be replaced with new gates/cells of same type base layers for applying ECOs

 

[sharas]

Re: Antenna fillers

Thanks.

In my company the methodolgy is indeed to place these spare antenna cells.

 

[joe2moon]

Re: Antenna fillers

Instead of antenna "filler" cell it sounds more likely to be "spare" antenna cell.

The reason why insert these kind of cells might be prepared for the coming metal-layer-only changes ECO.