Doping in Device Simulations

[Tom Jiao]

Hi, I am a new user to QuantumATK.  After following the IVStudyobject tutorial with the junctionless SOI structure, I changed the doping level to simulate the iv characterstics for a  nmos structure.   https://docs.quantumatk.com/tutorials/ivcharacteristics/ivcharacteristics.html

The resulten curve is attached and the subthreshold slope is a lot worse than the junctionless structure in the tutorial. I was expecting a better SS or at least similar levels. My question is that is my setup correct?  Is the central region and the electrode long enough for this doping level?

Thanks.

[Petr Khomyakov]

It would instructive to see Hartree Difference Potential / PLDOS  for the device calculated using the tutorial vs. new doping level adopted in your calculation.

Note that for low-dimensional systems such as films and nanowires one should use charge per atom units when setting doping level, meaning that one should recalculated e/cm**3 for bulk system to e/atom for low dimensional. The doping assumed in your calculation seems to be significantly larger than that adopted in the tutorial.