Frequently, numerical simulation methods are performed on a tessellation of the simulation domain. During different simulation stages of process simulation and device simulation several modules have to interact and the output data of one simulator has to be prepared as input for the next stage. To achieve flexibility in this interaction of the simulators, a set of tools concerning mesh generation was developed at the institute. With the use of third party data, often a conversion and adaption of the applied data to other data formats and representations is necessary. Especially for three dimensions, that incorporates a huge amount of data and resulting simulation times, a re-meshing of the domains, in particular, to adapt to the following simulation stage is necessary.
Arising from topography simulations often only a polygonal surface mesh is available. Therefore, the developed meshing tools cover the topics of format conversion to and from the in-house used data format, triangulation of the polygonal structures, volume mesh generation, and also visualization. Additionally, stages of data analysis, reparation of poorly shaped elements, and surface smoothing may be applied.
During meshing of the surfaces it has been shown that often poorly shaped elements are induced by the original simulation methods, which may be elements that are too dense from level-set calculations or elements with poor aspect ratios of the mesh edges arising from etching and deposition simulations. At the stage of surface meshing, it is relatively easy to perform a smoothing of the elements and to correct these short edges since no tetrahedrons exist that can degenerate and cause problems in the connectivity of the remaining tetrahedrons in later by a simulator. This aspect also improves the quality of the resulting triangular surface meshes and consequently also results in better quality of the generated volume meshes.
These tools are available under the ViennaMesh project and are still in progress. Currently, modules for mesh refinement are under development.