US 12,369,311 B2
Semiconductor device and manufacturing method thereof
Guangsu Shao, Hefei (CN); Deyuan Xiao, Hefei (CN); and Yunsong Qiu, Hefei (CN)
Assigned to CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN); and BEIJING SUPERSTRING ACADEMY OF MEMORY TECHNOLOGY, Beijing (CN)
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN); and BEIJING SUPERSTRING ACADEMY OF MEMORY TECHNOLOGY, BeiJing (CN)
Filed on Jun. 9, 2022, as Appl. No. 17/836,315.
Application 17/836,315 is a continuation of application No. PCT/CN2021/129356, filed on Nov. 8, 2021.
Claims priority of application No. 202110957060.2 (CN), filed on Aug. 19, 2021.
Prior Publication US 2023/0059600 A1, Feb. 23, 2023
Int. Cl. H01L 27/108 (2006.01); H10B 12/00 (2023.01)
CPC H10B 12/34 (2023.02) [H10B 12/053 (2023.02); H10B 12/482 (2023.02); H10B 12/488 (2023.02)] 15 Claims
OG exemplary drawing
 
1. A method for manufacturing a semiconductor device, in which the semiconductor device comprises a substrate, wherein the method comprises:
forming a plurality of first trenches extending in a first direction on the substrate;
forming a plurality of second trenches extending in a second direction on the substrate which the first trenches are formed on, wherein the first direction is perpendicular to the second direction, and a first depth of the first trenches is greater than a second depth of the second trenches;
forming a first isolation layer in at least one of the first trenches and at least one of the second trenches, wherein on a section along the second direction, first gaps are respectively provided between the first isolation layer and sidewalls on both sides of the first trench, and a depth of the first gaps is less than the first depth;
forming two bit lines which are parallel to each other and extend in the first direction by depositing conductive layers of a first conductive material at bottoms of the first gaps on both sides of the first trench; and
forming word lines extending in the second direction in the first trench and the second trench, and above the conductive layers in the first trench.