SFGEN Reference


Transformations may be applied to the input data (ODB++ or GDSII)





Offset (Edge Bias)

Order of Transformations

The transformations are performed in the following order: 1 Scaling
2 Mirror X
3 Mirror Y
4 Rotation
5 Translation (Shift)

all units are in microns except rotation which is in degrees

Test Data

For purposes of illustrating each transformation we will use the test file shown below. The extents are 500,000 um X 610,000 um and the data is centered at 0,0. It consists of "frame boundaries" on layer 1 and cells (1,2,3,4) with data on layer 2.


No transformations


Scaling can be independently applied in both X and Y and the anchor point for scaling can be specified by the user. In the example below a scale factor of 1.1 has been applied in X and 0.9 in Y with anchor at 0,0. In most practical cases, only very small scale factors are applied in order to account for substrate expansion or contraction.

after scaleX=1.1 and scaleY=0.9

Xscale=1.1,Yscale=0.9; extents are now 550,000 x 549,000 um.


The input data can be mirrored in X (about the Y axis), or mirrored in Y (about the X axis) or both. The position of the mirror line can be set.

MirrorX about the Y axis at X=0

MirrorX (about the Y axis at X=0)

Mirror Y (along X axis at Y=0)

MirrorY (about the X axis at Y=0)

MirrorX and MirrorY

MirrorX and MirrorY


The input data can be rotated around any user specified anchor point. Postive values of rotation move the data in the CCW direction.


Rotation about 0,0 of 10 degrees


Offset, also known as edge bias, compensates for etch factor. There are two different modes. Below you can see one of the geometries without any sizing applied.


Dimensions without any offset applied.

Both - if both is selected then the X and Y directions are sized equally. The illustration below shows the dimensions when a value = 5 um has been applied to both X and Y.

offset BOTH X,Y=5

Offset of 5 um in both X and Y

XYBoth - Allows independent offset (edge bias) values for X and Y. In the example below the X offset = 10 um and the Y offset = 20 um.

offset BothXY X=10 Y=20

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