US 11,908,732 B2
Alternating spacers for pitch structure
Hsueh-Chung Chen, Cohoes, NY (US); Chanro Park, Clifton Park, NY (US); and Koichi Motoyama, Clifton Park, NY (US)
Assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US)
Filed by INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US)
Filed on Sep. 15, 2021, as Appl. No. 17/475,829.
Prior Publication US 2023/0080746 A1, Mar. 16, 2023
Int. Cl. H01L 21/768 (2006.01); G03F 1/38 (2012.01); H01L 21/033 (2006.01); H01L 21/308 (2006.01)
CPC H01L 21/76816 (2013.01) [G03F 1/38 (2013.01); H01L 21/0337 (2013.01); H01L 21/3088 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method of forming a pitch pattern, comprising:
forming two adjacent mandrels separated by a first distance, D1, on a substrate;
forming a first set of alternating sidewall spacers between the two adjacent mandrels;
removing the two adjacent mandrels;
forming a second set of alternating sidewall spacers after removing the two adjacent mandrels; and
forming a third set of alternating sidewall spacers on opposite sides of the first set of sidewall spacers.
 
10. A method of forming a pitch pattern, comprising:
forming two adjacent mandrels separated by a first distance, D1, on a substrate;
forming a first sidewall spacer on opposite sides of each of the two adjacent mandrels, wherein the first sidewall spacers are made of a first material;
removing the two adjacent mandrels;
forming a second sidewall spacer adjoining each of the first sidewall spacers after the removing the two adjacent mandrels, where the second sidewall spacers are made of a second material different from the first material;
forming a third sidewall spacer adjoining each of the second sidewall spacers, where the third sidewall spacers are made of the first material; and
forming a fourth sidewall spacer adjoining each of the third sidewall spacers, where the fourth sidewall spacers are made of the second material.