5 Replies Latest reply on Aug 11, 2010 2:56 PM by karen_chow

    Measuring Metal Resistance

    spalania

      Hi all,

       

      I want to measure point to point resistance of a metal strip connected on a top level full chip GDS. I am able to highlight the metal strip for which I need to know the resistance using Calibre drc and various SVRF commands.

       

      But I am not getting how to measure the resistance of this metal strip, is it possible to do this while running Calibre drc on my GDS...???

       

      Thanks,

      Siva

        • 1. Re: Measuring Metal Resistance
          chris_balcom

          Hi Siva,

           

          If it is a simple strip and you would be satisfied with using just the perimeter and the area of the polygon to calculate the resistance then I think we could do that fairly easily with DRC. If it's more complicated with transistions through vias and multiple layers of metal then I'm not sure DRC will be able to do it. If it is one of the more complex situations then you may need xRC or PERC P2P (point to point resistance).

           

          Best regards,

          Chris

          • 2. Re: Measuring Metal Resistance
            spalania

            Thanks for your reply Chris.

             

            I would need to extract the metal resistance in both the cases.  Please let me know how to use SVRF commands to extract the resistance of a simple metal strip connecting point A to point B with out any vias or devices.

             

            I also need to extract the resistance in some cases where there is multiple metal jumps with vias inbetwee, but no active devices in the path.

             

            But is it possible to include xRC or PERC tools along with my DRC checks in a single run. I'have only the GDS as input.

             

            Thanks,

            Siva

            • 3. Re: Measuring Metal Resistance
              chris_balcom

              Hi Siva,

               

              I think there may be a few ways to perform very basic perimeter and area calaculations on a simple shape but I'm afraid I don't have time right now to create a working example or experiment. It might be a little more difficult if you don't already have SVRF rule writing experience. I could mention that some of the possibilities would be to use NET AREA RATIO with an EXPRESSION, but that's not really what the operation was intended for but if you're familiar with that operation you could probably hack something together for your purposes.

               

              DFM PROPERTY is another possibility. you can search for "measurement functions" in the SVRF manual for ideas about how to use AREA or PERIMETER with that operation.

               

              Another idea might be to use Calibre LVS connectivity extraction to create a netlist where those certain pieces of metal you were identifying, could be treated as simple resistors and you could use the builtin resistance calculation capability of the DEVICE operation.

               

              All of those ideas would take a bit of work or experimentation to get going, sorry I won't be able to do that right now.

               

              You asked about combining xRC or PERC and DRC but all of those are separate jobs, not something that runs inside DRC.

              1 of 1 people found this helpful
              • 4. Re: Measuring Metal Resistance
                spalania

                Thanks Chris for your reply. Let me try out what you've suggested with my little SVRF rule writing experience.

                • 5. Re: Measuring Metal Resistance
                  karen_chow

                  Hi! Most customers run Calibre xRC to calculate point to point resistance. There is a point2point report that can be specified.