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The Cross Section Button: Show Cross Section

The Cross Section button in the View Menu brings up a special sub-window which displays a cross sectional (side) view of the layers under an arbitrary line. After pressing the command button, the user is asked to define a line, which can be done by clicking twice or dragging. If the line covers any geometry, a sub-window showing the cross sectional view will appear. The process can be repeated. Pressing the Esc key will exit the command.

All geometry under the line will be shown, without regard to cell hierarchy.

If the Constrain 45 button in the Edit Menu is active, the angle is constrained to multiples of 45 degrees. If not set, the angle is unconstrained, but snaps to multiples of 45 degrees when the angle is close. In either case, pressing the Ctrl key removes the constraint.

The endpoints initially do not snap to grid points. The period (`.') key toggles snapping to grid of the initial (anchor) point while in the Cross Section command.

In the display, all layers are considered except those with the Symbolic keyword given. The Symbolic keyword can be given in technology file layer blocks or can be set from the Layer Parameter Editor from the Edit Tech Params button in the Attributes Menu. The Symbolic layers are ignored in the display. Layers that are invisible, as set with button 2 in the layer table, will contribute to the cross section topology, but will not be rendered.

The layer thickness shown can be set with the CrossThick technology file keyword. This can be applied in the physical layer blocks of the technology file, or can be set or edited from the Layer Parameter Editor.

If CrossThick is not set, the displayed thickness will be taken from the Thickness parameter from the extraction system, if the Xic program is in use. This parameter is not available in XicII or Xiv. The Thickness parameter can be set in a technology file used with Xic (in the physical layer blocks), or can be set or edited from the Extraction Parameter Editor from the Extract Menu.

If not set by either keyword, a default thickness is assumed. The variable XSectThickness, which sets the default thickness, can be set with the !set command. The value is a real number in the range 0.01 - 10.0 which represents the thickness in microns. If not set, a value of 0.5 microns is used.

In the display, the thicknesses are scaled proportionally so the layers will always be visible. They appear with actual thickness when the viewing area is sufficiently small.

Similarly, the polarity of the layer will be obtained from the CrossField parameter if set, in the technology file or with the Layer Parameter Editor. If CrossField is not given, and Xic is being run, the polarity will be that assumed in the extraction system. This polarity will be ``dark field'' if the DarkField keyword is given, which is implicit if either the Via or GroundPlaneClear keywords are given. In XicII and Xiv the extraction parameters are not available.

If CrossField has been given as ``dark'', or, in Xic, the CrossField keyword is not given and the DarkField attribute is set, the cross section will show the inverse of the layer as it appears in ordinary drawing windows. The CrossField keyword, if given in Xic, will override the polarity from the extraction system in the cross section display.

A via, for example, which appears as a colored square in the main window, should appear as a hole in cross section, since the painted area actually represents lack of insulating material. This is a ``dark field'' layer.


next up previous contents index
Next: The Rulers Button: Create Up: The View Menu: Alter Previous: The Peek Button: Show   Contents   Index
Stephen R. Whiteley 2012-04-01