Prev: 7.1 Simulation Model
Up: 7.1 Simulation Model
Next: 7.1.2 Meshing
7.1.1 Surface Extraction
The first step in the simulation sequence is the preparation of the
appropriate input for the meshing tool.
The initial geometry is built up with a solid modeling tool based on the same
cellular material representation as used for the deposition simulator
(cf. Chapter 3). Therefore the surface of the initial geometry as well as of
the geometries resulting after each timestep has to be extracted in a
triangular format, suitable as input for the meshing tool.
Figure 7.2:
Surface extraction from the cellular material representation (dashed lines) to
a triangle description (shaded triangles in solid lines) using a marching cube
algorithm and surface coarsening.

The conversion is accomplished with a marching cube algorithm [38]
which guarantees that all triangle points are in the center of the cell faces.
This is necessary for a nonambiguous correlation between triangle points and
surface cells. The only exception are points touching the horizontal bounding
box. In this case the points are located at the edges of the cubes still
permitting the nonambiguous correlation. After the initial triangulation
coplanar triangles are merged using a very small point to plane distance
criterion according to [66]. In this way a higher efficiency of the
following meshing and FEM steps is achieved without loosing any topography
information. An example of such a surface extraction can be seen in Fig. 7.2.
Prev: 7.1 Simulation Model
Up: 7.1 Simulation Model
Next: 7.1.2 Meshing
W. Pyka: Feature Scale Modeling for Etching and
Deposition Processes in Semiconductor Manufacturing