Physics of electronics

[ebrahim120]

I have a thin film of insulator material which has a thickness about 30 nanometer and on top of that I have a gate electrode which has a thickness of 50 nanometer that I use for creating a electric field thought the insulator layer. Usually people say the electric filed pattern after thin film is broadening, but recently I heard it is quit depend on the thickness of electrode and insulator layer, and how far I am measuring the field from electrode. Does anybody knows about this ?

 

[Harald Kapp]

What you are talking about is called a fringe field. A rather theoretical discussion is here.
On second thought you describe a MOSFET. You'll find information on this e.g. here and here.

And yes, the field will not be uniform but vary with location and distance from the electrode. Unfortunately I cannot quickly find a suitable reference - most refenreces assume a rather large capacitor with uniform field between the plates and ignore the edge effects.