During the past decade the demand for a robust and rigorous mesh generator for more complex structures has risen in the semiconductor industry. While a three-dimensional simulation was not possible in the beginnings, today's computers have made such a simulation feasible and desirable to be able to account for structure-dependent physical effects. Investigating the state of the art in other fields where three-dimensional mesh generation was applied longer ago is especially important to avoid limitations of earlier approaches and to meet the demands of the semiconductor industry.
Four different challenges for three-dimensional mesh generation can be identified:
- Automatic mesh generation without manual interference
- Mesh density grading, mesh element quality
- Complex devices composed of many internal and external boundaries
- Closed control volumes for the Box Integration Method
Concerning mesh grading one of the major issues is the balance between the number, the size, and the quality of the elements. The number should be minimized while the size has to satisfy local mesh density criteria. Often, the mesh is not optimally fitted to the desired mesh density, and too coarse or too fine elements exist in various areas of the simulation domain. Alternatively, the desired accuracy of the analysis cannot be achieved in all areas, or the subsequent tools and simulators are pushed to limits beyond the scope of an average workstation by a generally too fine mesh. An increased flexibility in mesh generation allowing rapid changes of the mesh density while keeping the overall element count low would be ideal.