Ground Plane Handling

The Ground Plane Handling group controls how the extraction system treats a ground plane. The is only required if the technology file defines a ground plane layer, which is unlikely to be true in semiconductor processing. The ground plane handling features were included specifically for Josephson junction process support, but can be applied to other technologies should the need arise.

Assume clear-field ground plane is global
If a clear-field ground plane has been identified in the technology file, when this box is checked, all areas of this layer are assigned group 0, the ground group. When not checked, only the largest area group in the top-level cell is assigned group 0. This tracks the GroundPlaneGlobal variable.

Invert dark-field ground plane for multi-nets
If a dark-field ground plane layer has been identified in the technology file, if this box is checked, the ground plane layer will be polarity inverted internally for extraction purposes. The inverted layer will be used to establish connectivity. This tracks the state of the GroundPlaneMulti variable.

Inversion method menu
When using an inverted ground plane, this menu provides a choice of methods. The default is to invert in each cell, then clip out the area occupied by subcells. The second choice will create the inverted layer in the top-level cell only, using the entire hierarchy as the source for geometry to invert. The third choice is similar, but will create the inverted layer in each cell, using as the source all geometry in that cell and its subcell hierarchy. This tracks the state of the GroundPlaneMethod variable.