Dummy poly effect on Id

[cmoslayoutguide]

How dummy poly which is placed next to the original gate, effects the Id of a transistor?

 

[erikl]

I think you cannot state a fixed or reproducible interrelationship between the transistor Id and a dummy poly structure next to it. The dummy poly just serves to maintain a (rather) similar ambient environment at the sides of the outer transistors as between them. Moreover the dummy screens the outside transistors from proximity effects (layout boundary, guard ring) due to STI stress. See this image from a CIC workshop: .