why insert filler cells into empty space?

[Simranjeet Singh]

LVS: Check wikipedia page. Its given very clearly over there.
https://en.wikipedia.org/wiki/Layout_Versus_Schematic

Timing Closure: By timing closure it means that all the timing criteria like setup and hold constraints are satisfied and the design works fine at the specified frequency thats all.

Filler Cells are nothing special...they are just empty cells used to fill the design to maintain a uniform density and for power and ground rail continuity.
The Diagram will explain the use of filler cells for Power continuity.**broken link removed**

Mask: It is simply an arrangement of opaque and transparent areas that is used to create a pattern.

Substrate, nwell, N+, P+ are all part of base layer..

 

[ivlsi]

The Diagram will explain the use of filler cells for Power continuity.Attachment 70258

Link to this attachment(diagram) is broken. Would you please re-create it?

 

[Simranjeet Singh]

Its opening in my case..anyway the image is below:
Image:

 

[ivlsi]

Thank you!

 

[chuggington]

Another question related to filler cellls, how do you decide which cell to use as the filler cell, IO filler cell etc ?