Help! LVS emergency! I'm using a custom MOM capacitor layout for my amplifiers and I need to somehow run LVS on that. I'm using `property device primitive`in magic to extract the capacitor as a blackbox. And I did a similar subcircuit in xschem - basically a 3-terminal box with nothing inside. However, LVS keeps failing. I'm attaching the comp.out file here I know I'm missing something obvious, but I don't know what. Halp plox, that's the last thing I have to solve for the tape-out!

The issue is that if you have two subcircuits that are being matched as primitive devices, the pin names need to match. The schematic side is showing "1", "2", "3" for the pins, which means that it did not see a subcircuit definition for it (which is normal with primitive devices). You probably will need a black-box (empty) entry for the subcircuit in the schematic netlist that has the named pins ("in", "out", and "gnd").

MIM capacitors have polarity, but I don’t think MOM capacitors do (you’d need to add a permute statement to the netgen setup). Why are you extracting the MOM capacitor as a 3 pin device? Is that due to the substrate connection? The easiest “solution” would be to remove the devices from your netlists and check that everything matched without the MOM caps.

@Mitch Bailey: Generally yes, you want to extract the substrate connection and model the capacitance from each side to substrate as well as the inter-layer capacitance. All of the SkyWater MoM capacitors have a substrate pin (and sometimes a separate shield pin).