SiC Extended Precision PiN Diode simulation

sicex01.in : SiC Extended Precision PiN Diode simulation

Requires: Blaze
Minimum Versions: Atlas 5.22.1.R

This example demonstrates simulation of a reverse SiC PiN Diode characteristic versus different levels of arithmetic precision.

Simulation of wide band gap semiconductor devices is challenging mainly because the intrinsic carrier concentration is small. One solution to overcome this problem is to artificially increase the intrinsic carrier concentration. A more rogorous method consists of using different levels of arithmetic precision.

For well-converged solutions, run-time increases with precision. The increase is especially significant at the highest precision levels.

On the other hand, certain problems (e.g. SiC devices) that have difficulty converging at the lower precision levels are likely to run faster if the precision level is increased. Accordingly, the optimum precision level for a particular problem is likely to be the minimum level that yields good convergence during the solution.

The maximum precision that may be required for a well-converged solution can be estimated from the semiconductor bandgap. However, it is often possible to simulate a given device, under particular bias conditions, using a precision less than this maximum. Conversely, we can say that a given precision level is supportive of bandgaps up to a certain value, and convergence may be difficult if materials with higher bandgaps are simulated.

SiC may need to be simulated using a nominal precision of 256-bits. However in this example and as mentionned above 128 bits precision is enough in this case.

In the first part of the input deck a simple SiC PiN diode is created. Then multiple breakdown voltage simulations are performed with different levels of arithmetic precision. The level of arithmetic precision is set in Atlas using the simflags="-128" parameter in the go atlas statement for a 128 bits precision.

All the simulation were performed with the SiC anisotropic Impact Ionization model

Simulation time are extracted for all simulations in deckbuild using extract name="t" clock.time

The results are plotted and overlayed in tonyplot showing that the Breakdown Voltage is independent of the precision used during the simulation. As mentionned above the 128 bits precision is enough to allow accurate simulation of the leakage current.

It is also interesting to notice that the simulation time as a function of precision exhibits a bell shape and confirm what we mentioned above.

To load and run this example, select the Load example button in DeckBuild. This will copy the input file and any support files to your current working directory. Select the run button to execute the example.