Example of simplified SONOS model

sonosex05.in : Example of simplified SONOS model

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

The example shows:

  • How to use the simplified SONOS model
  • How to charge the device using hot carrier gate current
  • How to erase the device using tunnelling

The device is set up in a similar way to the DYNASONOS model. The main difference is that the gate stack materials remain as insulators, they are not changed to wide bandgap semiconductors. The gate material parameters which will affect the simulation are the tunnel insulator effective masses, and the bandgap and affinity parameters.

In this example case a device with a a 5/15/10 nm ONO gate stack is constructed. It is still necessary to specify N.I on the INTERFACE statement, but the DYNASONOS model must be explicitly cleared by using the syntax ^DYNASONOS. The NITRIDECHARGE statement is not required.

In this example the N.CONCANNON parameter on the MODELS statement is set, and this also has the effect of enabling the Hot Electron energy balance model. The gate is given a positive bias, in order to attract hot electrons leaving the channel. The drain is then biased to half of the gate bias and the hot electrons follow field lines until they either leave the device or charge the traps at the edges of the Nitride region.

After the device is charged the threshold voltage is obtained. The structure field is also saved, enabling you to look at the trapped charge under the "Insulator Charge" field, in units of cm^2.

The device is then erased by applying a negative bias to the gate, with drain and source grounded. The structure file is saved and the threshold voltage measured.

The Idrain versus Vgate plots are shown for the uncharged, charged and erased state of the device.

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.