Yeh, you need to take into account the permittivity, of the dielectric, the area of overlap of the plates, A, and the the distance between them, d, using the equation:
Im just having a bit of trouble. Here is the question.
Calculate approximate capacitance a parallel plate type device would have on the wafer if the electrode dimensions where 150um by 50um and the thickness of the SiO2 (insulator) between the conductors was 1um.
I keep getting different (and stupid answers). Do i have to take into account the dielectric constant of the silicon dioxide (SiO2) or not?
Any help. I know it should be fairly straight forward. Im just getting confused by a few things.
Well, with your numbers I got a different answer, 29.25mF, a fairly large capacitance. I'm not sure what the constant is for silica, but this page:
Dielectric Constants of Materials
thinks 4.5, giving an even bigger capacitance.