Hi, I created a simple ring oscillator in magic and when I extracted parasitic RC, I get two pfets with length=0 and width=0. Any ideas on how to prevent these from showing up since I have to comment these devices in order for the ngspice testbench simulation to work. Here is the extraction commands I used and I've attached the resulting spice netlist:

extract do local

extract all

ext2sim labels on

ext2sim

extresist tolerance 10

extresist all

ext2spice lvs

ext2spice cthresh 0.01

ext2spice extresist on

ext2spice

@Kevin Guan I believe that parasitic extraction with magic is only valid on flattened layouts. Look like the spice netlist you attached still has a hierarchy.

Thanks! I will make the changes and see if that resolves this.