Filler cell definition clarification

[kpsr]

Hello Guys,


Recently I studied some where regarding filler cell like this can any one please explain the following statement in detail.

Filler cells also provide decoupling capacitance to complete the power connections in the standard cell rows and extend N-well and P-well regions.

Previously I thought about filler they will provide N & P well continuity after reading the above statement I am in confusion. If filler is working as decap then why we need decap cell. If any one please help me.

 

[whenkey]

Fillers never work as decap cells. Fillers are just to fill the gaps in the die and there is no transistor in it. Some people call decap cells as decap filles.

In some cases, to properly fabricate the lower metal layers (thin layers) there is some drc condition like minimum metal density. So to fix that DRC errors we have to insert filler cells contains some metal layers (just to maintain metal density over die area).

The cell which is used to provide physical connection to N-Well and P-Well is known as Well tie cell (Well tap cell or Well tap filler).

 

[kpsr]

Thank you for your answer.
I hope there are two types of fillers
1. Filler cell -> which gives N-well and P-well continuity
2. Metal filler -> which provides proper metal density.
Please correct me if any thing wrong.

 

[whenkey]

Thank you for your answer.
I hope there are two types of fillers
1. Filler cell -> which gives N-well and P-well continuity
2. Metal filler -> which provides proper metal density.
Please correct me if any thing wrong.

yes..

Metal Fillers,
Well tie filler,
Decap cells..