Nanopore MOSFET Model
The goal of this project was to model a 3D MOSFET utilizing a nanopore structure in Sentaurus and vary different parameters to see the effects on the device physics of the transistor.
Background
A nanopore is a funneling system that collects ions of two types, positive and negative ions. Knowing this, we can change the parameters of the nanopore to accumulate ions of our choice. Depending on what type of substrate the nanopore has, it can emit either holes or electrons to be funneled into the nanopore. For the collecting of ions to initiate, we must first bias voltage across the drain to source to add heat to the silicon (Si) substrate, the outer shells of the Si will emit electrons that are broken off of the atom due to the addition of the heat. Lastly, these electrons have the potential to be collected in the nanopore funnel, and if the ions remain in the nanopore, a successful memory device has been produced.
Changes to the parameters, such as relocating the nanopore from the center, will yield highly variable results. The current drain is much more present nearing the drain and center as opposed to the source, thus declaring crucial suggestions that tell us that input into the nanopore is not uniformly motivated along all the locations on the channel and that changing parameters such as channel length, and doping density of the substrate, and increasing or decreasing the voltage bias at the drain will yield varying ion gathering outcomes by the nanopore.
Parameters Changed
-
Position of Nanopore
-
Channel Length
-
Charge of Nanopore
-
Doping Density
-
Width of Device
Results
-
Position of nanopore
-
For the position of the nanopore, the center side created the highest output current when compared to other combinations of the position of the nanopore. The 0.01 nm location gave the best drain current, while the 0 nm position came in close second.
-
-
Different channel lengths
-
Plotting the I-V curves for our carefully selected channel lengths, the channel length of 7 nm gave us the maximum current difference when compared to other lengths.
-
-
Amount of charges in the Nanopore
-
Plotting the I-V curves for our different concentrations, for a concentration of 2 M, we achieved a maximum current difference when compared to other concentrations.
-
-
Doping density
-
After plotting the I-V curves for 3 different doping densities, we saw a maximum output current difference for two doping concentrations: 5e+18 and 5e+19 cm-3.
-
-
Width
-
After testing the model for 5 different widths, we plotted the I-V curves and found a maximum current difference for a width of 35 nm.
-