Jacki wrote on Apr 23rd, 2014, 4:17pm: Only the devices are modeled with this junction diode, but in the region where MIM cap and guarding ring, it is not modeled.
I'm not sure I understand what you're saying. I think you mean, in the extraction, the junction diode is only extracted under MOSFET devices (I guess it's NMOS in deep nwell). And the extraction does not include the diode under MIM caps or guard rings.
Do you know the doping level of the psub or dnw? Can you make some estimates of the capacitance based on the extraction of junction diodes under differently-sized MOS devices?