US 12,289,882 B2
Semiconductor device including air gap structure above word line
Luguang Wang, Hefei (CN)
Assigned to CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed on Jul. 20, 2022, as Appl. No. 17/869,206.
Application 17/869,206 is a continuation of application No. PCT/CN2021/135743, filed on Dec. 6, 2021.
Claims priority of application No. 202111202026.0 (CN), filed on Oct. 15, 2021.
Prior Publication US 2023/0118276 A1, Apr. 20, 2023
Int. Cl. H10B 12/00 (2023.01)
CPC H10B 12/34 (2023.02) [H10B 12/053 (2023.02)] 18 Claims
OG exemplary drawing
 
1. A semiconductor device, comprising:
a substrate, a first groove and a second groove located in the substrate, wherein the second groove is formed by etching the substrate downwards from part of a bottom surface of the first groove, and a sidewall of the second groove retracts inward by a preset length relative to a sidewall of the first groove;
a word layer comprising a first sub-portion located in the second groove and a second sub-portion located in the first groove, wherein a gap is provided between a sidewall of the second sub-portion and the sidewall of the first groove; and
a word line cover layer located in the first groove and covering the second sub-portion, wherein an air gap structure at least located at the gap is provided in the word line cover layer.