Q: What Types of 3D Delaunay Shape Refinement can be used in Victory Process?

A. The Victory Process cell mode Delaunay 3D device meshing algorithm already includes various TCAD-based local refinement algorithms to ensure accurate and robust device simulation. These include junction and interface distance refinement. One benefit of these approaches is that complex refinement behavior can be specified via a simple deck interface, but a limitation is that the results can only vary according to the small number of parameters of the schemes. In some cases, such as particle path refinement, it can be useful to have finer, more local control over the mesh and the shape distance refinement schemes have been produced to support this.

Victory Process can operate in either 1, 2 or 3-dimensions and can produce one of two different geometric representations: cell mode and process mode. Cell mode structures are generally composed of large, flat geometric parts but process mode structures may be smoothly varying and only very locally flat. Device meshes of cell mode structures resolve the input shape precisely but this is undesirable for the case of process mode structures as it would result in very finely sampled meshes which would be unsuitable for device simulation.

Q. How can I Crop and Slice using a non-convex mask during the export?

Non-Convex Mask Polygons
Non-Convex Mask Polygons

Previous Victory Process releases have supported convex polygon cropping, slicing and mirroring support. It is also now possible to use non-convex polygons for either cropping or slicing.

In Figure 1 an example of a non-convex polygon crop and slice in the cell mode victory (delaunay) export is given. Note that the deck syntax is identical to the convex case.

2D Crop, Slice and Mirror

It is possible to perform the crop, slice and mirror (process and/or device) in the 2D exports.

An example of this functionality is given in Figure 3, where a crop and slice is shown. It should be noted that the coordinates specified in the polygon mask are those in the 2D export and not the 3D grid that the export is taken from (i.e., only X/Y need to be specified even though this cutplane is XZ).

The solution of linear systems lies in the core of any TCAD simulation. On any nonlinear step of the computation a linear system needs to be solved. The size and condition number of the matrices in these linear systems vary significantly depending on the specific type of TCAD simulation. So in order to achieve fast convergence it is required that the linear solver has good performance, good accuracy, can handle cases of ill-conditioned matrices, and it would be nice if the solver works well on any size linear system.