Checking Edge Separation

Comments

• stockstephanie

  June 11

  For anyone else that needs a similar solution, I ended up doing something more like:

  violation = ((((NWELL.and(OXIDE)).not(GATE)).interacting(GATE, 1, 1)).edges.and(OXIDE.edges)).with_length(0.001.um, 0.999.um)
  

  This seems to be a viable solution for what I needed, but if there are any improvements to be made I would love to hear them! I needed the random interacting statement in order to ignore oxide between two gates.
• Matthias

  June 11

  Hi @stockstephanie,

  You need to use "enclosing", not "separation".

  Here is an example:

  

  And this is my script:

  report("discussion 2875")
  
  poly = input(1, 0)
  active = input(2, 0)
  nwell = input(3, 0)
  
  gate = poly & active
  
  gate_sides = gate.edges.not(active.edges)
  violation = nwell.edges.enclosing(gate_sides, 1.0.um, projection) 
  
  violation.output("nwell not enclosing gate by >= 1µm")
  

  The explanation is this: edges are not just thin lines, they also have a direction. If you look from start to end, the left side of the edge is "outside", the right side is "inside" (edges run along the polygons in clockwise direction).

  When you use a DRC function on edges, their relative orientation gives the relation: edges facing each other with the "inside" side fulfil the "width" relation, edges facing each other with the "outside" side fulfil the "separation", "space" or "notch" relation. In your case, the edges stem from an enclosing relation, hence the enclosing check still applies.

  I hope this explanation makes sense.

  Matthias
• stockstephanie

  June 12

  That works so much better! Thanks, that helps a ton : )