Three-dimensional flash memory having improved degree of integration, and manufacturing method therefor
AssigneeSamsung Electronics Co., Ltd.
InventorYunheub Song
Life of this patent
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Abstract
Provided are a 3-dimensional (3D) flash memory with an improved degree of integration and a method of manufacturing the same. The 3D flash memory may include at least one vertical string formed to extend in one direction on a substrate and comprising a channel layer formed to extend in the one direction and a charge storage layer formed to extend in the one direction so as to surround the channel layer; a plurality of electrode layers stacked to be vertically connected to the at least one vertical string; and a source line formed to be buried in the substrate.
Claims20
A method of manufacturing a 3-dimensional (3D) flash memory, the method comprising:
- etching a part of a substrate;
- generating a first sacrificial layer in a space in which the part of the substrate was etched;
- forming at least one vertical string on the substrate comprising the first sacrificial layer to extend in one direction;
- generating a plurality of electrode layers stacked to be vertically connected to the at least one vertical string;
- and
- removing the first sacrificial layer to form a source line to be buried in the substrate in a space from which the first sacrificial layer was removed.
A 3-dimensional (3D) flash memory comprising:
- a plurality of vertical strings extending in a vertical direction, each vertical string comprising a channel layer extending in the vertical direction and a charge storage layer extending in the vertical direction and surrounding the corresponding channel layer,
- wherein the plurality of vertical strings comprise a first group of vertical strings each having a first horizontal cross-sectional area and a second group of vertical strings each having a second horizontal cross-sectional area, wherein the first horizontal cross-sectional area is greater than the second horizontal cross-sectional area, and
- wherein the first group of vertical strings each comprise memory cell transistors each configured to store n bits and the second group of vertical strings each comprise memory cell transistors each configured to store m-bits, where n and m are positive integers and n is greater than m.
A method of manufacturing a 3-dimensional (3D) flash memory comprising a plurality of vertical strings extending in a vertical direction, each vertical string comprising a channel layer extending in the vertical direction and a charge storage layer extending in the vertical direction and surrounding the corresponding channel layer, the method comprising:
- forming a plurality of vertical holes in a mold structure on a substrate, the mold structure comprising a plurality of sacrificial layers and a plurality of insulating layers that are alternately stacked, including
- with a first etching process, forming a first group of vertical holes in the mold structure, and
- subsequent to the first etching process, with a second etching process, forming a second group of vertical holes in the mold structure;
- and
- forming a first group of the vertical strings in the first group of vertical holes and forming a second group of the vertical strings in the second group of vertical holes.
Dependencies are inferred from the claim text.