GDS-SR is a step and repeat utility designed to take a die (in GDSII format) and step it to create a whole wafer mask.

The stepping is simple and intuitive and designed to fill in a round wafer with an (optional) flat on the bottom.

Advanced Mask Functions

In addition to generating the stepped array, there are several advanced functions incorporate into GDS-SR in order to help a designer produce a complete wafer mask ready for the photomask shop that does not need further intervention or CAD work.

This includes the ability to mix multiple die, to remove die and to replace selected die with special devices for alignment or calibration.

GDS-SR is designed to step a cell over a whole wafer. It can even take into account a flat on the bottom of the wafer.

Reticle Input

For wafer level masks, the foundry often supplies stepping information of the reticle - GDS-SR can take reticle step information (even with mixed products) and create the required array in only a few mouse clicks. It does all computations necessary to determine which die are inside the wafer.

Drop In Target and Test Cells

generally, some of the arrayed cells are replaced with alignment targets or test cells which have been designed to have the exact same shape but with different "contents.". GDS-SR allows the user to click on an existing arrayed cell and replace it with the cell of his choice.

Automatic Collar Generation

The mask designer often has to create a dark field region which exactly follows the edge of the arrayed die. This can only be done after stepping and is often "hand drawn" The edge becomes extremely difficult to draw if the circuits are small and the array is staggered.

GDS-SR's collar generator uses boolean operations to find the outer "edge" of the array and produces a dark field polygon out to the edge of the mask.

In addition, the user can define multiple rectangular cutouts that will be filled with targets or mask labels.

Automation - Scripting

GDS-SR can be run in fully automatic mode by creating a resource file containing the required inputs and directives. Ideal for automation and integration with manufacturing database software.

Staggered Stepping

Some MEMs need not be stepped into a rectangular array with a constant street width between circuits. If the parts are separated by chemical etching and the basic cell is not rectangular, then there may be staggered steppings which produce more circuits per square mm of wafer area.