Multiple-Patterning Photolithographic Mask and Method

A method of forming an integrated circuit device, the method comprising:

• receiving a substrate and a mask having a plurality of sub-reticles;
• aligning the substrate and the mask;
• performing a first photolithographic sequence including:
• performing a first plurality of exposures on the substrate using the mask to form a first plurality of exposed areas of the substrate;
• and
• shifting an alignment of the mask relative to the substrate between the first plurality of exposures such that the first plurality of exposed areas do not overlap;
• thereafter shifting the alignment of the mask relative to the substrate by an intermediate shift increment that includes a partial pitch shift;
• and
• performing a second photolithographic sequence including:
• performing a second plurality of exposures on the substrate using the mask to form a second plurality of exposed areas of the substrate;
• and
• shifting the alignment of the mask relative to the substrate between the second plurality of exposures such that the second plurality of exposed areas do not overlap.

A photomask comprising:

• a mask substrate;
• and
• a reticle containing first, second, third, and fourth sub-reticles,
• wherein the first, second, third, and fourth sub-reticles contain first, second, third, and fourth subsets of device features, respectively;
• wherein the first, second, third, and fourth subsets of device features are different;
• and
• wherein the first, second, third, and fourth sub-reticles correspond to first, second, third, and fourth photolithographic exposures, respectively, of a multiple patterning photolithographic process.