2T or 3T model of resistor

Dear All,

I am working with a finfet based PDK and noticed that there are two options available for the high-R resistor: 2 terminal or 3 terminal. In my understanding, there should be no difference between the two since high R is by itself a thin film based resistor and therefore the body terminal connection should not matter. (First question, am I right in saying this ?) I used the 2T model and removed the implant and threshold voltage creation options, since again in my understanding, it should not matter. The circuit passed DRC, LVS and ERC and simulated fine.

If I do not remove the implant option, ERC fails with floating p-sub warning. I want to understand if my choice of 1) removing the implant layer and 2) using 2T device is correct or not ? Any insights will be helpful.

Best Regards.

In general, model of a resistor contains a resistor (that should not depend on the third trminal presence or bias condition), and a capacitor (and this one will depend on the presence of a floating well - floating well will reduce the parasitic capacitance).

Floating psub error is not related to the resistor, you just probably forgot to put a tap and add a connection to the psub.

You would use the 3-terminal model for anything RF
(presuming there's not an even more sophisticated
one offered) to represent the shunt-C distributed
across the resistor area, and "to where?".

There is no ohmic connection but there are still AC
currents.

The thin film resistor is also potentially a field MOS
gate and carries with it, in bad cases, a C-V swing
that adds nonlinearity to RF circuits. So a hard heavy
implant below, eliminates nonlinear AC currents (but
on the minus side, lowers the series resistance to
the field below the resistor - which can make the
effects of the shunt-C worse than (say) putting the
resistor over a lighter doped (high resistivity or even
intrinsic) region, which is a common thing for RF in
CMOS, both JI and SOI.

Device recognition rules and ERC are going to check
for consistency of construction between all of the
implants and so on. If you read the rules deck you
can probably figure out what it's complaining about
(although PCells placed from schematic ought to
deliver the sought consistency, "you break it, you
bought it" once you start touching polygons one
by one.