Semiconductor memory structure and method for preparing the same
AssigneeNanya Technology Corporation
InventorWEI-MING LIAO
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Abstract
The present disclosure provides a semiconductor memory structure including a substrate, a plurality of first trenches disposed in the substrate, a plurality of second trenches disposed in the substrate and spaced apart from the first trenches, a plurality of buried digit lines disposed in the first trenches, and a plurality of buried word lines disposed in the second trenches. The first trenches include a first depth, and the second trenches include a second depth. The second depth of the second trenches is greater than the first depth of the first trenches. Top surfaces of the buried word lines are lower than bottom surfaces of the buried digit lines.
Claims20
A semiconductor memory structure comprising:
- a substrate;
- a plurality of first trenches disposed in the substrate, the first trenches comprising a first depth;
- a plurality of second trenches disposed in the substrate and spaced apart from the first trenches, wherein the second trenches comprises a second depth greater than the first depth;
- a plurality of buried digit lines disposed in the first trenches;
- and
- a plurality of buried word lines disposed in the second trenches,
- wherein top surfaces of the buried digit lines are lower than bottom surfaces of the buried word lines.
A method for preparing a semiconductor memory structure, comprising:
- providing a substrate comprising a plurality of active regions extending in a first direction;
- forming a plurality of first trenches in the substrate, the first trenches comprising a first depth and extending in a second direction different from the first direction;
- forming a plurality of buried digit lines in the first trenches;
- forming a plurality of second trenches in the substrate, the second trenches comprising a second depth and extending in a third direction different from the first direction and the second direction;
- deepening portions of the second trenches to form a plurality of third trenches in the substrate, the third trenches comprising a third depth;
- and
- forming a plurality of buried word lines in the third trenches.
Dependencies are inferred from the claim text.