Mask data preparation (MDP)
Beginner
The factory’s work of turning the chip file into instructions for the machines that make the stencils.
Novice
The steps between tapeout and mask writing: chip finishing (adding a seal ring and fill), placing the chip on the reticle with test patterns and alignment marks, optical proximity correction, and fracturing every shape into the rectangles and trapezoids a mask writer can draw.
Expert
Input is GDSII or OASIS; output is in the mask writer’s own format. Data volume explodes along the way, especially after OPC, which is why compact formats and processing that keeps the hierarchy matter.
Explained in GDS & tapeout (Design Flow).
See also: Optical proximity correction (OPC), Photomask.