Minimum Required Version
: Expert 4.14.0.R, Guardian 4.14.0.R

Since the advent of deep-micron processes, many dummy metal patterns are added in
layout designs for planarization. They are created as regularly aligned based on some
rules, and usually created by a DRC tool.

Correspondingly,
Guardian DRC
provides the command Create_Rectangles to create an array
of rectangles with specified dimensions and spacing.

The following script is an example of how to create a dummy metal pattern using this command:

   Create_Rectangles: Size=(5um, 8um), Offset=(1um, 1um),
                      Space=(3um), Layer=&bulk, LayerR=&tmp11;
   Size: layer=METAL1, value=3, layerR=&tmp12;
   Select: relation=OVERLAP, options=(NOT),
           layer1=&tmp11, layer2=&tmp12, layerR=METAL1_Dummy;
 

The first command creates rectangles in the whole area of the layout, with specified
dimension, space, and offset. The next command resizes the METAL1 by the minimum
spacing of METAL1, to keep enough clearance between the already-existing METAL1 wires
and the newly-created dummy patterns. And, the final command removes the created
rectangles overlapping with the already-existing METAL1 wires, and the rest of them
becomes the dummy metal patterns.

This kind of operations will be done for all the METAL layers.

The actual operation steps to check the command behaviors are as follows:

1) Start
Expert
.

2) Run
File->Open
, load the project file
guardian_example_27.eld
, and then open the top cell.
It contains some METAL1 wires and VIA rectangles.

3) Run
Verification->DRC->DRC Script Panel
, and then
File-> Open
in the script panel to load
the sample DRC rule file
guardian_example_27.dsf.

4) Run the loaded DRC script by
DRC->Run in the DRC script panel
.
As a result, a dummy metal pattern will be created in the whole area of the layout design.

5) Set all the layers invisible except for the METAL1 and METAL1_Dummy, in order to
observe the created dummy metals that are not overlapping with the original METAL1
objects, see
Figure 1
.

To learn more about Guardian DRC, the different commands and their syntax as well as
the different setup options, see the Guardian DRC user manual
“guardian_users1.pdf” located in lib/expert/4.14.0.R/docs/ in your installation area.

Output Results

Input Files

guardian_example_27.dsf

Update_Layout: layers=(METAL1_Dummy, METAL2_Dummy, METAL3_Dummy);

substrate: layerR=&bulk;

Create_Rectangles: Size=(5um, 8um), Offset=(1um, 1um),
                   Space=(3um), Layer=&bulk, LayerR=&tmp11;
size: layer=METAL1, value=3, layerR=&tmp12;
select:relation=OVERLAP, options=(NOT),
       layer1=&tmp11, layer2=&tmp12, layerR=METAL1_Dummy;

// Create_Rectangles: Size=(5um, 8um), Offset=(2um, 2um),
// Space=(3um), Layer=&bulk, LayerR=&tmp21;
// size: layer=METAL2, value=3, layerR=&tmp22;
// select:relation=OVERLAP, options=(NOT),
//        layer1=&tmp21, layer2=&tmp22, layerR=METAL2_Dummy;

// Create_Rectangles: Size=(5um, 8um), Offset=(3um, 3um),
// Space=(3um), Layer=&bulk, LayerR=&tmp31;
// size: layer=METAL3, value=3, layerR=&tmp32;
// select:relation=OVERLAP, options=(NOT),
//        layer1=&tmp31, layer2=&tmp32, layerR=METAL3_Dummy;