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The first part of the paper describes the interfacing between ECAD tools
and the numerical simulators.
The main problem is to generate a three-dimensional simulation grid out
of layout data and process information.
As ECAD layout data are usually available in CIF or GDSII format,
the first step is to convert these files to our general geometry data
format [2].
Specifying the simulation domain of interest as small as necessary
minimizes the CPU time consumption of the simulation.
This can be done interactively with our graphical layout editor which
provides functions to cut smaller domains out of large layout
designs (Fig. 1 and Fig. 5).
As ECAD layouts may contain overlapping polygons, we have developed
a two-dimensional solid modeler which performs Boolean operations to
generate a non-overlapping, consistent representation of the mask geometry.
Mask information combined with process parameters is used to perform basic
process steps, like deposition with constant thickness, to construct the
final polygonal three-dimensional structure (Fig. 2 and
Fig. 6).
Therefore the mask specified by the deposition process step is projected
on the surface of the geometry which was obtained from the previous process
step, the created faces are merged with the previous geometry and extended
to the third dimension.
This projection method applied to arbitrary surfaces enables the
generation of moderate non-planar structures.
We utilized a layer-based method [3] to generate a tetrahedral
simulation grid automatically.
By using tetrahedral elements a boundary-conform grid can be constructed
also for layout designs with slanted edges and non-planar structures.
Next: MATHEMATICAL MODELS
Up: No Title
Previous: INTRODUCTION
Rainer Sabelka
1998-01-30