Mask data preparation

Mask data preparation (MDP), also known as layout post processing, is the procedure of translating a file containing the intended set of polygons from an integrated circuit layout into set of instructions that a photomask writer can use to generate a physical mask.

[1] Mask data preparation requires an input file which is in a GDSII or OASIS format, and produces a file that is in a proprietary format specific to the mask writer.

Although historically converting the physical layout into data for mask production was relatively simple, more recent MDP procedures require various procedures:[1] Special considerations in each of these steps must also be made to mitigate the negative affects associated with the enormous amounts of data they can produce; too much data can sometimes become a problem for the mask writer to be able to create a mask in a reasonable amount of time.

Because mask fracturing is such a common procedure within the whole MDP, the term fracture, used as a noun, is sometimes used inappropriately in place of the term mask data preparation.

When a chip is to be manufactured, the individual die typically is repeated several times in the form of a matrix on the final reticle, This reticle layout includes horizontal and vertical scribe lines that enable later separation of individual dies after chip fabrication.