Geometric based signature – EU patent issuance

Grenoble – July 19th, 2022 –

XYALIS,  is proud to announce that the European Patent Office (EPO) has granted our European patent EP3740889B1 (June 22, 2022). In this patent, XYALIS provides a new method to compare layout databases using a geometric based signature.

Patent abstract

The invention concerns a method of generating a digital signature of a geometric design represented by a geometric design file. The method involving generating the digital signature based on a single axis projection of the geometric design.

Geometric based signature

When different teams exchange different versions of the same layout, it is critical to know if the database has changed. The geometric signature can be used to compare different versions of the same layout regardless of the format used to describe this layout. Nowadays, the microelectronic industry uses widely GDSII or OASIS® format. The designers use new tools that manipulate either format. Therefore to check for any difference after conversion, they use generally a tool that makes a XOR between the files. But this operation can be time and memory consuming especially with huge databases. The tool must access to both files to make the XOR operation.

Using the geometric based signature, XYALIS helps teams to reduce the time and resources needed for these operations. With this new method, the signature of the reference file is generated only once. Then only the signature of the converted file will be compared. The signature is a unique file which associates each technology layer with a checksum based on the geometric envelop of the layer’s polygons. It is independent of the layout file format and of the design description strategy.

Geometric based signature

Find more information about this patent in the TechDesign article “Layout-database file control: the missing link“.

XYALIS has also developed a tool (GOTdiff) that allows to compare 2 databases regardless of their format using this patent.


XYALIS, an Electronic Design Automation (EDA) company, focuses on two main flows of the layout finishing process: Mask Data Preparation and Metal Filling to address Chemical Mechanical Polishing (CMP) issues.


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