Methods and structures for forming uniform fins when using hardmask patterns
A method for manufacturing a semiconductor device includes forming a hardmask layer on a substrate, patterning the hardmask layer to form a plurality of patterned hardmask portions on the substrate, depositing a dummy hardmask layer on the substrate, patterning the dummy hardmask layer to form a plurality of patterned dummy hardmask portions on the substrate, wherein each of the plurality of patterned dummy hardmask portions is positioned adjacent respective outermost patterned hardmask portions of the plurality of patterned hardmask portions, and transferring a pattern of the plurality of patterned hardmask portions and the plurality of patterned dummy hardmask portions to the substrate to form a plurality of fins and a plurality of dummy fins from the substrate.
1. A method for manufacturing a semiconductor device, comprising:
forming a hardmask layer on a substrate;
patterning the hardmask layer to form a plurality of patterned hardmask portions on the substrate;
depositing a dummy hardmask layer on the substrate;
patterning the dummy hardmask layer to form a plurality of patterned dummy hardmask portions on the substrate, wherein each of the plurality of patterned dummy hardmask portions is positioned adjacent respective outermost patterned hardmask portions of the plurality of patterned hardmask portions;
transferring a pattern of the plurality of patterned hardmask portions and the plurality of patterned dummy hardmask portions to the substrate to form a plurality of fins and a plurality of dummy fins from the substrate; and
forming a spacer layer on the dummy hardmask layer.
2. The method according to claim 1 , wherein a distance between a patterned dummy hardmask portion and an adjacent outermost patterned hardmask portion is the same or substantially the same as a distance between two adjacent patterned hardmask portions.
3. The method according to claim 1 , wherein a width of a patterned dummy hardmask portion is the same or substantially the same as a width of a patterned hardmask portion.
4. The method according to claim 1 , further comprising removing portions of the spacer layer to form a plurality of spacers on the dummy hardmask layer.
5. The method according to claim 4 , wherein a width of a spacer of the plurality of spacers is the same or substantially the same as a width of a patterned hardmask portion.
6. The method according to claim 4 , wherein the plurality of spacers cover portions of the dummy hardmask layer, and wherein the patterning of the dummy hardmask layer comprises removing remaining portions of the dummy hardmask layer not covered by the plurality of spacers.
7. The method according to claim 6 , further comprising removing the plurality of spacers from the plurality of patterned dummy hardmask portions.
8. The method according to claim 1 , wherein the plurality of patterned hardmask portions and patterned dummy hardmask portions cover portions of the substrate and the transferring comprises etching remaining portions of the substrate not covered by the plurality of patterned hardmask portions and patterned dummy hardmask portions to form the plurality of fins and dummy fins.
9. The method according to claim 8 , wherein the etching is performed to a depth including an active height of the plurality of fins.
10. The method according to claim 9 , further comprising removing the plurality of patterned dummy hardmask portions from the plurality of dummy fins.
11. The method according to claim 10 , further comprising further etching remaining portions of the substrate not covered by the plurality of patterned hardmask portions, including the plurality of dummy fins to a depth below the active height of the plurality of fins.
12. The method according to claim 11 , further comprising forming a dielectric layer on the substrate to a height below the active height of the plurality of fins.
13. The method according to claim 8 , wherein a width of each of the plurality of fins is the same or substantially the same.