Method for forming semiconductor memory device with sacrificial via
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsSheng-Chih Lai, Chung-Te Lin
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Abstract
A method for forming a semiconductor memory device is provided. The method includes forming a sacrificial via in a dielectric layer over a substrate, forming a first active layer over the dielectric layer, forming an insulating layer over the first active layer, and forming a second active layer over the insulating layer. The method also includes forming a trench through the second active layer, the insulating layer and the first active layer and corresponding to the sacrificial via, removing the sacrificial via to form a via hole in the dielectric layer, and filling the trench and the via hole with a conductive material.
Claims20
A method for forming a semiconductor memory device, comprising:
- forming a sacrificial via in a dielectric layer over a substrate;
- forming a first active layer over the dielectric layer;
- forming an insulating layer over the first active layer;
- forming a second active layer over the insulating layer;
- forming a trench through the second active layer, the insulating layer and the first active layer and corresponding to the sacrificial via;
- laterally etching the insulating layer from the trench to form a recess;
- forming a channel feature in the recess;
- removing the sacrificial via to form a via hole in the dielectric layer;
- and
- filling the trench and the via hole with a conductive material.
A method for forming a semiconductor memory device, comprising:
- forming an interconnect structure over a substrate, the interconnect structure including an access line in a dielectric layer;
- forming a sacrificial via in the dielectric layer and on the access line;
- and
- forming a memory cell array over the interconnect structure, comprising:
- forming a stack of layers over the dielectric layer, the stack of layers including active layers interposed by an insulating layer;
- cutting the stack of layers to form first source/drain features and second source/drain features spaced apart from the first source/drain features by a trench;
- etching the sacrificial via through the trench to form a via hole exposing the access line;
- and
- depositing a conductive material in the trench and the via hole.
A method for forming a semiconductor memory device, comprising:
- forming a plurality of sacrificial vias in a dielectric layer;
- forming a stack of layers over the dielectric layer;
- etching the stack of layers to form a first trench, wherein the first trench overlaps the plurality of sacrificial vias;
- etching the plurality of sacrificial vias to form a plurality of via holes;
- filling the plurality of via holes and the first trench with a conductive material to form a plurality of first conductive vias and a first gate structure, respectively;
- and
- cutting the first gate structure to form a plurality of first gate lines corresponding to the plurality of first conductive vias.
Dependencies are inferred from the claim text.