Sraf control method and system for wafer exposure, and mask manufacturing method using the method

A sub-resolution assist feature (SRAF) control system comprising:

• a processor;
• and
• a memory storing instructions,
• wherein when executed by the processor, the instructions cause the processor to perform operations comprising:
• obtaining an SRAF corresponding to a mask and a plurality of control points that were preset for the SRAF;
• generating a plurality of fake polygons for adjusting the SRAF on a virtual grid on a substrate where the mask and the SRAF are positioned;
• defining weights between centers of the plurality of fake polygons and the plurality of control points, wherein the weights are respectively greater as distances between the centers of the plurality of fake polygons and the plurality of control points decrease;
• adjusting the SRAF based on the weights that were defined and size variations of the plurality of fake polygons to reduce edge placement error (EPE) between the mask and a layout pattern corresponding to preset defocus and dedose conditions for the mask, while preventing printing of the SRAF on a wafer;
• generating design data for the mask as a corrected layout image based on the SRAF that was adjusted;
• and
• transmitting a control signal to perform exposure on the wafer based on the mask.

A mask manufacturing method performed by a computing device, the mask manufacturing method comprising:

• obtaining a sub-resolution assist feature (SRAF) corresponding to a mask and a plurality of control points that are preset for the SRAF;
• generating a plurality of fake polygons for adjusting the SRAF on a virtual grid on a substrate where the mask and the SRAF are positioned;
• defining weights between centers of the plurality of fake polygons and the plurality of control points, wherein the weights are respectively greater as distances between the centers of the plurality of fake polygons and the plurality of control points decrease;
• and
• adjusting the SRAF based on the weights that were defined and size variations of the plurality of fake polygons to reduce edge placement error (EPE) between a layout pattern corresponding to preset defocus and dedose conditions for the mask and the mask, while preventing printing the SRAF on a wafer;
• obtaining design data for the mask;
• transmitting the design data as mask tape-out (MTO) design data;
• preparing mask data based on the MTO design data;
• and
• transmitting a control signal to perform exposure on the wafer based on the mask data.