Hard masks for block patterning
Embodiments are directed to a method of forming a semiconductor device and resulting structures having a hard masks for sidewall image transfer (SIT) block patterning. The method includes forming a first hard mask on a substrate. Spacers are formed on the first hard mask, and a second hard mask is formed over the spacers. The second hard mask and a portion of the first hard mask are concurrently removed by the same hard mask removal process to expose a surface of the substrate. After concurrently removing the second hard mask and portions of the first hard mask, the heights of the spacers are substantially equal.
1. A method for forming a semiconductor device, the method comprising:
forming a first hard mask on a substrate;
forming a plurality of spacers on the first hard mask;
forming a second hard mask over the plurality of spacers; and
concurrently removing the second hard mask and a portion of the first hard mask to expose a surface of the substrate.
2. The method of claim 1 further comprising:
forming a gap filling layer over and between the plurality of spacers;
removing a portion of the second hard mask to expose a surface of the gap filling layer in a first region; and
removing a portion of the gap filling layer in the first region to expose a portion of the first hard mask.
3. The method of claim 1 further comprising:
forming a planarization layer on the substrate; and
forming a dielectric layer on the planarization layer, the dielectric layer between the planarization layer and the first hard mask.
4. The method of claim 1 , wherein height dimensions of each of the plurality of spacers after concurrently removing the second hard mask and portions of the first hard mask are substantially equal.
5. The method of claim 1 , wherein a material of the first hard mask and a material of the second hard mask are selected such that the first and second hard masks are removable using a single etch.
6. The method of claim 1 , wherein the first hard mask comprises TiN or TiOxNy and the second hard mask comprises Ti.
7. The method of claim 6 , wherein the second hard mask comprises TiARC or TiOx.
8. The method of claim 7 , wherein the second hard mask further comprises a refractory index of about 1.5 to about 1.7 and an absorbance value of about 0.1 to about 0.4.
9. The method of claim 7 , wherein the second hard mask further comprises about 10 percent to about 20 percent carbon.
10. A method for forming a semiconductor device, the method comprising:
forming a first hard mask on a substrate;
forming a first spacer in a first region on the first hard mask and a second spacer in a second region on the first hard mask;
forming a gap filling layer over and between the first and second spacers;
forming a second hard mask on the gap filling layer, a first portion of the second hard mask over the first spacer in the first region and a second portion of the second hard mask over the second spacer in the second region;
removing the second portion of the second hard mask to expose a surface of the gap filling layer in the second region;
removing a portion of the gap filling layer in the second region to expose a portion of the first hard mask; and
concurrently removing the first portion of the second hard mask and the exposed portion of the first hard mask.
11. The method of claim 10 further comprising:
forming a planarization layer on the substrate; and
forming a dielectric layer on the planarization layer, the dielectric layer between the planarization layer and the first hard mask.
12. The method of claim 10 , wherein a height of the first spacer after removing the first portion of the second hard mask is substantially equal to a height of the second spacer.
13. The method of claim 10 , wherein a material of the first hard mask and a material of the second hard mask are selected such that the first and second hard masks are removable using a single etch.
14. The method of claim 10 , wherein the first hard mask comprises TiN or TiOxNy and the second hard mask comprises Ti.
15. The method of claim 14 , wherein the second hard mask comprises TiARC or TiOx.
16. The method of claim 15 , wherein the second hard mask further comprises a refractory index of about 1.5 to about 1.7 and an absorbance value of about 0.1 to about 0.4.
17. The method of claim 15 , wherein the second hard mask further comprises about 10 percent to about 20 percent carbon.