After routing at the stage of filler cells adding to the design::
can we add all spare cells in the design instead of filler cells. ofcourse filler cells will be used for N-well continuity between standard cells.
But why dont we use spare cells instead of fillers..
While fabricating the chip the fabricator should fabricate the spare cells(at transistor level) like std cells at that time also we'l have N-well continuity, then why dont we prefer spares instead fillers??
What will be the draw back if we use spares in empty places of design??
Can some one please explain....