@User: The best way to make a cap (or most devices, for that matter) in magic is to use the Devices menu; e.g.,

Devices 2

->

MiM cap - 1fF/um^2 (metal3)

, which will draw the entire capacitor for you, or at least show you an example valid layout. We have not taped out a chip with this device, but we have one on its way, and the Calibre run from SkyWater didn't flag any issues with the MiM caps, so apparently they're okay.