Every software package contains a full set of examples suitable for that version and are installed with the software. If you see examples here that are not in your installation you should consider updating to a later version of the software. These examples can be used by beginners and advanced users for product evaluation, teaching purposes, and self-training.

Required Modules

Victory Process

• 3D Structure Editor

Victory Mesh

• 3D Meshing

Victory Device

• 3D Simulator
• 3D TFT

Although various design and physical effects have been successfully analysed in 2D, it becomes important to start to analyse and predict device performance dependent on layout effect with 3D simulations. We will show in the following example here that a complete 3D process and device simulation solution is available to address future challenges in TFT design. Using SILVACO tools, designers can accelerate and optimize the development of for next generation display technologies.

This example demonstrates 3D a-Si:H TFT simulation using 3D process simulation Victory Process and 3D device simulation Victory Device.

In order to create the 3D structure, we used Victory Process 3D process simulator. Victory Process is very suitable for 3D TFT devices simulation since it is layout driven, accurate, fast, and easy to use. The 3D structure creation takes only few minutes. The particularity of the structure under test is that non 90-degree side-wall was used but 45 degree instead. After the process simulation is done a 3D structure is saved using a tetrahedron mesh to ensure that any shape created during 3D process simulation is well conserved and transferred to Victory Device for further device simulation.

Disordered materials contain a large number of defect states within the band gap of the material. To accurately model devices made of polycrystalline or amorphous materials, we need to consider these defects. Victory Device can model interface states as well as defect states. Defect states is a combination of two exponentially decaying band tail states and two Gaussian distributions of mid-gap states. In addition to the defect models, band to band tunneling model was used to simulate accurately TFT devices in reverse. Device simulations were performed using 80 bits extended precision. It is very interesting to notice that due to the specific 3D effect the simulated IDVD curve when we reverse the source and the drain are different.

The e.field.derivs parameter causes Victory Device to consider the partial derivatives of the field-dependent band to band tunnelling model with respect to the gradient of the potential. Including these derivatives slows down the computation and is usually not necessary, but in this case, it helps the convergence.

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