Retention example : Retention example

Requires: S-Pisces
Minimum Versions: Atlas 5.22.1.R

The example shows:

  • How to create a SONOS device structure
  • How use the PF.NITRIDE model
  • How to study the long term retention properties of the device

The device is set up using Atlas mesh commands to make a dielectric stack of 4 nm of Silicon oxide, 5 nm of Silicon Nitride and 10 nm of Sapphire (Al2O3).

The device is charged for 1 millisecond with a Gate Bias of 18 V, before the SOLVE INIT SONOS statement resets all electrode biases to zero, while preserving the fixed charge density in the Silicon Nitride and protecting the free charge densities in the insulator stack from numerical problems.

The device is simulated for up to 10 years, with progressively increasing step sizes. It saves out the structure files at preset time points, so that you can look at the change in charge profile and the (negative) Sonos electron charging rate as time progresses. To do this, use the TonyPlot cutline tool to create sections through the gate stack. The overall stored charge is shown in the logfile, and can be seen to be much diminished after 3 x 10^8 seconds

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.