The design community is typically quite familiar with the concept of a DRC, or design rule check. A design is typically verified through the use of a DRC prior to tape-out. A DRC typically consists of minimum width and space checking and perhaps some other verification processes.
CATS supports what we refer to as an MRC, or a manufacturing rule check. This differs from a DRC only in the type of data that may be verified. Where DRC's are typically limited to analyzing design data, CATS' MRC may be used to flag minimum width and space violations in design data, fractured E-beam data, inspection data, PG data, or even jobdecks.
The value of a typical DRC is limited to the design world. While it helps designers verify that the original design does not violate minimum width or space criteria, it does not ensure that the data manipulations common to the fracturing and jobdeck set-up phases of data preparation.
And not only can CATS' MRC help verify that these post tape-out manipulations have not violated design rules, they can also be used to ensure that the part can be manufactured given the constraints of the exposure and inspection systems available.
For example, the data below shows a case where CATS space checking has located a sub micron space. This could be critical to the mask maker whose exposure tool, process, or inspection system may be either incapable of producing that part or at the very least may wish to know that the condition exists so that it can be carefully checked throughout the manufacturing and inspection process.