US 11,690,214 B2
Dynamic random access memory and method for manufacturing the same
Hung-Yu Wei, Taichung (TW); Pei-Hsiu Peng, Taichung (TW); and Wei-Che Chang, Taichung (TW)
Assigned to WINBOND ELECTRONICS CORP., Taichung (TW)
Filed by Winbond Electronics Corp., Taichung (TW)
Filed on Sep. 22, 2021, as Appl. No. 17/481,772.
Claims priority of application No. 110100250 (TW), filed on Jan. 5, 2021.
Prior Publication US 2022/0216210 A1, Jul. 7, 2022
Int. Cl. H10B 12/00 (2023.01); H01L 29/06 (2006.01)
CPC H10B 12/315 (2023.02) [H01L 29/0649 (2013.01); H10B 12/482 (2023.02); H10B 12/488 (2023.02)] 20 Claims
OG exemplary drawing
 
1. A dynamic random access memory, comprising:
a buried word line in a substrate, wherein the buried word line extends along a first direction;
a bit line on the substrate, wherein the bit line extends along a second direction perpendicular to the first direction;
a bit line contact structure below the bit line;
a capacitive contact structure adjacent to the bit line; and
an air gap structure surrounding the capacitive contact structure, wherein the air gap structure comprises:
a first air gap at a first side of the capacitive contact structure, wherein the first air gap exposes a shallow trench isolation structure in the substrate; and
a second air gap at a second side of the capacitive contact structure, wherein the second air gap exposes a top surface of the substrate, wherein the first air gap connects to the second air gap.