In the discussion to follow, the ``source'' is the material of the object being checked, either a layer (on which the rule is defined) or a layer expression result if the Region specification is given. The ``target'' is the set of figures associated with the expression supplied to the rule, for those rules that take an expression.
The rules described in this section are ``edge tests'' where the region of interest is generally a small constructed area along an edge. The test is applied for each applicable edge portion of each source figure. The constructed area is rectangular, parallel to the source figure edge, and may extend out of the source figure, or into the source figure. These extend only along the parts of the source figure edge where certain conditions apply, as will be described. The width of the test area (perpendicular to the figure edge) is the dimension associated with the rule.
We find the edge portions of a source figure as follows. We iterate through the edges. For each edge, we construct a unit-width test area that extends outside of the figure. We throw out the parts of the edge where the test area intersects ``source compatible figures'', meaning the same layer or layer expresion as the source. Thus we throw out the part of the edge which is not really an edge, but a boundary between dark areas of the same type and is therefor not a physical discontinuity. The resulting edge portion is the starting point for further restrictions that are rule-specific.
Below is a table which identifies the edge portions identified for the built-in rules, and the test performed.
|rule||where||test||src out||trg in||trg out|
The first column specifies the built-in rule name of the ``edge'' rules. These will be described in more detail below. The where column indicates the direction of the constructed test area along a source figure edge, either projecting into the figure or outside of the figure. The test indicates the type of test to perform in the constructed area. These are
The three remaining columns indicate the part of the source figure edge that is used to construct the test area. These indicate the required coverage of the source material just outside the edge, and target material just inside and just outside of the edge. The possibilities are
So, for example, for MinSpaceTo, we take the part of the edges that are not covered by source just outside of the edge, and not covered by target just inside of the edge. The test will pass if the constructed area, which extends out of the figure, intersects no target material.
Each of the ``edge'' rules recognize two additional keywords:
``The minimum distance to CO from a NP/PP butt edge over OD is 0.06 microns.''
This can be implemented as
MinSpaceTo Region OD Inside !PP Outside PP CO 0.06
MinSpaceTo Region OD Inside !NP Outside NP CO 0.06
The built-in edge rules are described in more detail below. In each, for simplicity we will use the following as an abbreviation for the syntax elements:
EdgeArgs = [Region region_expr] [Inside inside_expr] [Outside outside_expr]