GDSII

The gdsii file extension is associated with GDSII, which is the standard file format for transferring / archiving 2D graphical design data. It contains a hierarchy of structures, each structure containing elements situated on layers. It is a binary format that is platform independent, because it uses internally defined formats for its data types.

The pattern data is considered to be contained in a library of cells. Cells may contain geometrical objects such as polygons (boundaries), paths, and other cells. Objects in the cell are assigned to layers of the design. Different layers typically represent different processing steps for exposure on separate mask plates. Geometrical objects may also be tagged with datatypes, which can be used for any purpose, but are most commonly used to group together similarly sized objects for compensation of the proximity effect.

The GDSII format specification limits the number of vertices per polygon (boundary) and wire (path) to not more than 200 pairs of coordinates. However, many packages, including LinkCAD, can read up to the technical maximum of 32,766 coordinate pairs. By default, when exporting to GDSII, LinkCAD will not write more than 200 vertices and larger polygons and wires are split into fragments. You may remove this limitation in the GDSII export options.