US 11,887,859 B2
Method for forming active region array and semiconductor structure
Erxuan Ping, Hefei (CN); Zhen Zhou, Hefei (CN); and Yanghao Liu, Hefei (CN)
Assigned to CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed on Jul. 12, 2021, as Appl. No. 17/372,878.
Application 17/372,878 is a continuation of application No. PCT/CN2021/078068, filed on Feb. 26, 2021.
Claims priority of application No. 202010134688.8 (CN), filed on Mar. 2, 2020.
Prior Publication US 2021/0343537 A1, Nov. 4, 2021
Int. Cl. H01L 21/308 (2006.01); H10B 12/00 (2023.01)
CPC H01L 21/3086 (2013.01) [H10B 12/053 (2023.02); H10B 12/34 (2023.02)] 18 Claims
OG exemplary drawing
 
1. A method for forming an active region array, comprising the following steps:
providing a substrate;
forming a first mask layer on a surface of the substrate, a first etched pattern being provided in the first mask layer;
forming a second mask layer covering a surface of the first mask layer;
forming a third mask layer having a second etched pattern on a surface of the second mask layer;
forming a flank covering a sidewall of the second etched pattern;
removing the third mask layer to form a third etched pattern between adjacent flanks;
etching the first mask layer along the third etched pattern to form a fourth etched pattern in the first mask layer; and
etching the substrate along the first etched pattern and the fourth etched pattern, to form multiple active regions in the substrate.