US 11,699,591 B2
Two-color self-aligned double patterning (SADP) to yield static random access memory (SRAM) and dense logic
Fee Li Lie, Albany, NY (US); Dongbing Shao, Wappingers Falls, NY (US); Robert C. Wong, Poughkeepsie, NY (US); and Yongan Xu, Albany, NY (US)
Assigned to Tessera LLC, San Jose, CA (US)
Filed by Tessera LLC, San Jose, CA (US)
Filed on Jun. 28, 2021, as Appl. No. 17/360,819.
Application 17/360,819 is a continuation of application No. 16/796,614, filed on Feb. 20, 2020, granted, now 11,062,911.
Application 16/796,614 is a continuation of application No. 15/842,841, filed on Dec. 14, 2017, granted, now 10,573,528, issued on Feb. 25, 2020.
Prior Publication US 2021/0343536 A1, Nov. 4, 2021
Int. Cl. H01L 21/308 (2006.01); H01L 21/033 (2006.01); H01L 21/311 (2006.01); H01L 21/3065 (2006.01); H01L 21/8234 (2006.01); H01L 29/66 (2006.01); H01L 27/088 (2006.01); H01L 29/78 (2006.01); H10B 10/00 (2023.01)
CPC H01L 21/3086 (2013.01) [H01L 21/0332 (2013.01); H01L 21/0335 (2013.01); H01L 21/0337 (2013.01); H01L 21/3065 (2013.01); H01L 21/3081 (2013.01); H01L 21/3085 (2013.01); H01L 21/31116 (2013.01); H01L 21/823431 (2013.01); H01L 27/0886 (2013.01); H01L 29/6681 (2013.01); H01L 29/66795 (2013.01); H01L 29/785 (2013.01); H10B 10/12 (2023.02); H10B 10/18 (2023.02)] 20 Claims
OG exemplary drawing
 
1. A method of forming a static random access memory (SRAM) region, the method comprising:
providing (i) a first set of mandrels corresponding to a first lithography process and (ii) a second set of mandrels corresponding to a second lithography process, wherein a first mandrel of the first set of mandrels is adjacent to a first mandrel of the second set of mandrels;
forming spacers on the first and second sets of mandrels within approximately a same time interval during which a spacer layer deposition and etch process occurs; and
removing the first and second sets of mandrels to form an intermediate SRAM fin pattern, the intermediate SRAM fin pattern comprising:
first and second intermediate SRAM fins corresponding to spacers on opposing sidewalls of the first mandrel of the first set of mandrels; and
third and fourth intermediate SRAM fins corresponding to spacers on opposing sidewalls of the first mandrel of the second set of mandrels, wherein the second and third intermediate SRAM fins are adjacent intermediate SRAM fins,
wherein a pitch between the third and fourth intermediate SRAM fins corresponds to a width of the first mandrel of the second set of mandrels plus a width of a spacer, and
wherein a pitch between the second and third intermediate SRAM fins corresponds to a width of a space between the first mandrel of the first set of mandrels and the first mandrel of the second set of mandrels minus the width of a spacer.