Query on necessity Filler Cells in a small custom design - Virtuoso

[wipshami]

Hi ,

I am doing a custom design in virtuoso (Digital) in which I am connecting all Nwell & Pwell manually to VDD and GND . Then do I really need filler cells before a tapeout?

Thanks

 

[kenambo]

Hi,

Yes of course this filler and capacitors are needed to be included in the design ...It is used for device encapsulation and to avoid uneccessary effects of fields that causes the chage in Bulk(silican die) properties...

and you can route to VDD and GND using place and Route tool..

Thanks,...

- - - Updated - - -

Hi,

I forgot to tell an important thing about Fillers..

In IC fabrication, Chemical Mechanical Planarisation(CMP) is used to get High level planarisation... and it causes two adverse effects...

1) Dishing effect
2)oxide Erosion

To avoid these effects Dummy fill is used....

These are reduced by these "Dummy fill"...

Thanks..

 

[wipshami]

Hi,

Is dummy fill not metal fill ? are they same as filler cells ?
You mean even though there is nwell continuity , still we need filler ?

(just for more clarification)

Thanks

 

[kenambo]

Hi,

it is also a metal fill...
yes and these Dummy fillers can connected to either VDD or GND or left floating...

Try this PDF.. you may get clear IDea..

Thanks