oaAllowedSpacingRange (oacAllowedSpacingRange)

Description

The oacAllowedSpacingRange layer constraint specifies a range of allowed spacings between shapes on a layer. Spacing can be independent of the width of the shapes, dependent on the width of one of the shapes, or dependent on the width of both shapes. This constraint uses an range array table to represent an array of oaIntRange values. If spacing is dependent on one or both shape widths, the width values are used as the array table lookup key. A single value can be specified for both the upper and lower bounds of the range, which means that the clearance for this range must be precisely the specified value. Multiple allowed ranges and discrete values can be specified.

Constraint at a Glance

Constraint type:	oaLayerConstraint
Value types:	oaIntRangeArrayValue, oaIntRangeArray1DTblValue, oaIntRangeArray2DTblValue
Database types:	oaTech
Object types:	oaAppObject

Values

The following value types are supported by this constraint:

oaIntRangeArrayValue
This value specifies that the spacing is independent of width.

Units: DBU
oaIntRangeArray1DTblValue
This value specifies that the spacing is dependent on the width of one of the two shapes

Units: DBU
oaIntRangeArray2DTblValue
This value specifies that the spacing is dependent on the width of both shapes.

Units: DBU

Parameters

The following parameters are supported by this constraint:

Name	Value Type	Units	Default	Description
width oacWidthConstraintParamType	oaIntValue	DBU	None	This parameter specifies that the constraint applies when both widths of adjacent shapes are less than the given width value.
parallelRunLengthTable oacParallelRunLengthTableConstraintParamType	oaBooleanValue	Boolean	False (only valid for value types: oaIntRangeArray1DTblValue)	If this parameter is true, then the index into the 1D table is the parallel run length between two shapes, rather than the width.

Examples

Manufacturing Reasons

Some foundries define a range of spacings allowed between minimum sized gates in order to facilitate proper insertion of assist or scattering bars. By defining the range of allowed spacings, foundries can ensure that the correct number of scattering bars can be inserted and that the gates print on the mask correctly.