CPC H10B 12/315 (2023.02) [H01L 29/0649 (2013.01); H10B 12/482 (2023.02); H10B 12/488 (2023.02)] | 20 Claims |
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.
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