Method of manufacturing photomask set for forming patterns, and method of manufacturing semiconductor device using the photomask set
A method of manufacturing a photomask set includes: preparing a mask layout, the mask layout including a plurality of first layout patterns apart from one another in a first region, wherein distances between center points of three first layout patterns adjacent to one another from among the plurality of first layout patterns respectively have different values; grouping pairs of first layout patterns, in which a distance between two first layout patterns adjacent to each other does not have a smallest value, and splitting the mask layout pattern into at least two mask layouts; and forming a photomask set including at least two photomasks each including a mask pattern corresponding to the first layout pattern included in each of the mask layout patterns split into at least two mask layouts.
1. A method of manufacturing a semiconductor device, the method comprising:
forming a plurality of bit-line structures having bit-lines extending in parallel to one another in a first horizontal direction on a substrate;
forming a plurality of buried contacts filling lower portions of spaces between the plurality of bit-line structures on the substrate; and
forming a plurality of landing pads by using a photomask set including a first photomask and a second photomask, the plurality of landing pads filling upper portions of spaces between the plurality of bit-line structures and extending onto the plurality of bit-line structures, and including a first landing pad, a second landing pad, and a third landing pad adjacent to one another, wherein a triangle connecting center points of top surfaces of the first landing pad and the second landing pad, and the third landing pad includes a scalene triangle,
wherein forming the plurality of landing pads includes:
forming a landing pad material layer filling the upper portions of the spaces between the plurality of bit-line structures and covering the plurality of bit-line structures,
forming a plurality of first hardmask patterns on the landing pad material layer by using the first photomask,
forming a plurality of second hardmask patterns by using the second photomask in a space between the plurality of first hardmask patterns on the landing pad material layer, and
patterning the landing pad material layer by using the plurality of first hardmask patterns and the plurality of second hardmask patterns as etching masks.
2. The method as claimed in claim 1 , wherein forming the plurality of landing pads includes aligning the plurality of landing pads in a row having a base distance between center points of top surfaces in a second horizontal direction orthogonal to the first horizontal direction and in a zigzag pattern in the first horizontal direction.
3. The method as claimed in claim 2 , wherein each of the first photomask and the second photomask includes an even layout pattern and an odd layout pattern alternately corresponding to the rows arranged in the second horizontal direction from among the plurality of landing pads.
4. The method as claimed in claim 2 , wherein each of the first photomask and the second photomask includes an even layout pattern and an odd layout pattern alternately corresponding to the rows arranged in a zigzag pattern in the first horizontal direction from the plurality of landing pads.
5. The method as claimed in claim 4 , wherein the plurality of first hardmask patterns and the plurality of second hardmask patterns, from among the plurality of landing pads, each alternately corresponds to rows in which a distance between center points of top surfaces has a value greater than the base distance, the rows that are arranged in zigzag in the first horizontal direction.
6. The method as claimed in claim 1 , wherein forming the plurality of landing pads includes forming an edge of a top surface of each of the plurality of landing pads into a circle.
7. A method of manufacturing a semiconductor device, the method comprising:
forming a plurality of word-lines extending in parallel to one another in a first horizontal direction across a plurality of active regions on a substrate, in which the plurality of active regions is defined by an isolation layer;
forming, on the substrate, a plurality of bit-line structures having bit-lines extending in parallel to one another in a second horizontal direction orthogonal to the first horizontal direction;
forming, on the substrate, a plurality of buried contacts filling lower portions of spaces between the plurality of bit-line structures and connected to the plurality of active regions;
forming a plurality of landing pads by using a photomask set including a first photomask and a second photomask, the plurality of landing pads being connected to the plurality of buried contacts, filling upper portions of spaces between the plurality of bit-line structures, extending onto the plurality of bit-line structures, and each having a circle-shape top surface; and
forming, on the plurality of bit-line structures, a plurality of storage nodes connected to the plurality of landing pads,
wherein the forming of the plurality of landing pads includes:
forming a landing pad material layer filling upper portions of spaces between the plurality of bit-line structures and covering the plurality of bit-line structures;
forming a plurality of first hardmask patterns and a plurality of second hardmask patterns apart from the plurality of first hardmask patterns, on the landing pad material layer, by sequentially using the first photomask and the second photomask; and
patterning the landing pad material layer by using the plurality of first hardmask patterns and the plurality of second hardmask patterns as etching masks,
wherein lengths of three sides of a triangle connecting center points of top surfaces of three landing pads adjacent to one another from among the plurality of landing pads respectively have a base distance having a value of 3 F (feature size), a first side distance greater than the base distance, and a second side distance less than the base distance, and
in the forming of the plurality of storage nodes, lengths of three sides of a triangle connecting center points of top surfaces of three storage nodes adjacent to one another from among the plurality of storage nodes have a value of 3 F (feature size).
8. The method as claimed in claim 7 , wherein the plurality of first hardmask patterns and the plurality of second hardmask patterns alternately correspond to rows arranged in the first horizontal direction from among the plurality of landing pads, respectively.
9. The method as claimed in claim 7 , wherein the plurality of first hardmask patterns and the plurality of second hardmask patterns, from among the plurality of landing pads, alternately correspond to rows arranged in zigzag in a second horizontal direction, the rows in which a distance between center points of top surfaces includes the first side distance, respectively.
10. The method as claimed in claim 7 , wherein each of the first photomask and the second photomask is a reflective-type mask for an Extreme Ultraviolet (EUV) lithography process.