Methods and system for determining pitch of lithographic features

A method of preventing photolithographic mask problem sites, the method comprising:

• generating a plurality of reference auxiliary features for a plurality of actual or simulated reference contacts representative of a randomly selected subset of a plurality of actual contacts of a mask design;
• determining a minimum separation distance between the plurality of reference contacts based on lithographic printing parameters;
• determining a bias of the plurality of reference contacts, separated by the minimum separation distance, by analyzing projections established by enlarging the areas of the reference contacts of the plurality of reference contacts;
• applying the determined bias to the plurality of actual contacts of the mask design;
• determining interactions of the biased plurality of actual contacts by determining interactions of portions of edges of ones of the biased plurality of actual contacts with projections of adjacent others of the biased plurality of actual contacts;
• and
• determining pitches of the biased plurality of actual contacts based on the determined interactions of edges.

A method of manufacturing a semiconductor device from a photomask designed using processor-executed instructions, comprising:

• generating a plurality of reference lithographic features corresponding to an actual or simulated less than all of actual lithographic features of a mask layout;
• generating a plurality of reference sub-resolution assist features for the plurality of reference lithographic features;
• determining a bias based on establishing mask positions for the generated reference lithographic and sub-resolution assist features according to one or more reticle or lithographic machine operating parameters, and determining an enlargement amount for which the generated reference lithographic and sub-resolution assist features in the established positions will cause interactions;
• applying the determined bias to all of the actual lithographic features of the mask layout;
• and
• determining pitch based on interactions of the biased all of the actual lithographic features.