Intrinsic Stress Effect on AlGaN/GaN HEMT IdVg Characteristic

ganfetex05.in : Intrinsic Stress Effect on AlGaN/GaN HEMT IdVg Characteristic

Requires: SSuprem 4/Victory Stress/Blaze
Minimum Versions: Athena 5.22.3.R, Victory Stress 2.22.4.R, Atlas 5.28.1.R

This example demonstrates:

  • Construction of the heterojunction structure using Athena syntax
  • Stress simulation, Material and models parameter specification
  • Simulation of Id/Vgs characteristics
  • Display of the results in TonyPlot

The device under consideration is a simple AlGaN/GaN HEMT. The 2D structure is obtain by Athena and the stress distribution is simulated by VICTORYSTRESS. This example produces stress distributions via the stress-liner made of nitride (tensile or compressive). Note that the stressor in this example is used to illustrate strain polarization, on top of lattice and spontaneous polarization.

The polarization model that supports dependency on loaded strain tensor has been used in this example. The model is enabled by the POLARIZATION flag of the MODELS statement.

The main concept of GaN based power devices is to use epitaxial strain to create 2DEG. The polarization model that supports epitaxial strain due to lattice mismatch is enabled by the CALC.STRAIN flag on the MODEL statement.

When both models are set in the simulation both the imported strain and the lattice mismatch calculation are accounted for.

The lattice and imported strain dependent components of polarization can be independently scaled using the scale factors TENSO.SCALE and PIEZO.SCALE on the MODEL statement. By default these are set to 1.0.

When enabling the POLARIZATION flag spontaneous polarization is automatically included in the calculation. The size of the spontaneous component can be scaled using the PSP.SCALE parameter of the MODELS statement.

After the initial solution is obtained the drain voltage is ramped to 1 V, then the IdVg characteristic is extracted from Vg=-5 to Vg=1.0 V.

The effect of strain is seen on IdVg characteristic. For illustration purpose we combined, in this example, different intrinsic stress (compressive or tensile) leading to different stress distribution and sign in the channel and the source and drain region. As a result IdVg curves change accordingly.

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