How to set the correct ref concentration for diffusion doping?

- March 8, 2022 at 10:42 am
  
  Mariah Ha
  Subscriber
  
  Hi,
  Most of the lumerical examples with silicon material use ref concentration doping as 1e+06 (cm-3). Why this value exactly? How do I set the correct value for this parameter . In my case I am using a constant doping of (1e+15) all over the structure , and (1e+19) as peak concentration in the diffusion doping region. Should the ref concentration be set to (1e+15) in this case?
- March 9, 2022 at 6:18 pm
  
  kghaffari
  Ansys Employee
  
  Hi As you know the ref concentration indicates the minimum value for the diffusion type doping. I think a concentration of 1e6 cm-3 is negligible, so as long as the value is small enough the chosen number in our examples is arbitrary.
  In your case I recommend visualizing the doping once you set up the simulation; for this mesh the structure and visualize grid>N. Does the profile match your intended doping? Using a constant doping as you described is a good way to fix the minimum doping value across the entire simulation.
  Best regards