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US 11,889,696 B2Granted
Memory arrays comprising strings of memory cells and methods used in forming a memory array comprising strings of memory cells
AssigneeMicron Technology, Inc.
InventorsJohn D. Hopkins, Nancy M. Lomeli
Life of this patent
Estimating the term…
Abstract
A memory array comprising strings of memory cells comprises laterally-spaced memory blocks individually comprising a vertical stack comprising alternating insulative tiers and conductive tiers. Channel-material-string structures of memory cells extend through the insulative tiers and the conductive tiers. The channel-material-string structures individually comprise an upper portion above and joined with a lower portion. Individual of the channel-material-string structures comprise at least one external jog surface in a vertical cross-section where the upper and lower portions join. Other embodiments, including method are disclosed.
Claims22
A method used in forming a memory array comprising strings of memory cells, comprising:
- forming a lower portion of a stack that will comprise vertically-alternating first tiers and second tiers, the stack comprising laterally-spaced memory-block regions, material of the first tiers being of different composition from material of the second tiers, a lowest of the first tiers comprising first sacrificial material;
- forming horizontally-elongated lines in a next-lowest first tier that are individually between immediately-laterally-adjacent of the memory-block regions;
- the lines comprising second sacrificial material;
- forming the vertically-alternating first tiers and second tiers of an upper portion of the stack above the lower portion and the lines,
- forming channel-material-string structures that extend through first tiers and the second tiers in the upper portion to the lowest first tier in the lower portion;
- forming horizontally-elongated trenches into the stack that are individually between the immediately-laterally-adjacent memory-block regions and extend to the line there-between;
- removing the second sacrificial material of the lines through the trenches;
- and
- forming intervening material in the trenches and void-spaces left as a result of the removing of the second sacrificial material of the lines.
6 more elements
A method used in forming a memory array comprising strings of memory cells, comprising:
- forming a conductor tier comprising conductor material on a substrate;
- forming a lower portion of a stack that will comprise vertically-alternating first tiers and second tiers above the conductor tier, the stack comprising laterally-spaced memory-block regions, material of the first tiers being of different composition from material of the second tiers, a lowest of the first tiers comprising first sacrificial material;
- forming horizontally-elongated troughs in the lowest portion that extend to the conductor tier;
- oxidizing exposed portions of the conductor material of the conductor tier;
- after the oxidizing, forming horizontally-elongated lines in the troughs that are individually between immediately-laterally-adjacent of the memory-block regions, the lines comprising second sacrificial material;
- forming the vertically-alternating first tiers and second tiers of an upper portion of the stack above the lower portion and the lines,
- forming channel-material-string structures that extend through first tiers and the second tiers in the upper portion to the lowest first tier in the lower portion;
- forming horizontally-elongated trenches into the stack that are individually between the immediately-laterally-adjacent memory-block regions and extend to the line there-between;
- removing the second sacrificial material of the lines through the trenches;
- and
- forming intervening material in the trenches and void-spaces left as a result of the removing of the second sacrificial material of the lines.
8 more elements
A method used in forming a memory array comprising strings of memory cells, comprising:
- forming a conductor tier comprising conductor material on a substrate;
- forming a lower portion of a stack that will comprise vertically-alternating first tiers and second tiers above the conductor tier, the stack comprising laterally-spaced memory-block regions, material of the first tiers being of different composition from material of the second tiers, a lowest of the first tiers comprising first sacrificial material;
- forming horizontally-elongated troughs in the lowest portion that extend to the conductor tier;
- laterally recessing the second-tier material of the second tier that is immediately-above the lowest first tier to form laterally-opposed recesses longitudinally-along individual of the troughs;
- after the recessing, forming horizontally-elongated lines in the troughs that are individually between immediately-laterally-adjacent of the memory-block regions, the lines individually comprising laterally-opposing projections longitudinally-there-along that are in the laterally-opposed recesses, the lines comprising second sacrificial material;
- forming the vertically-alternating first tiers and second tiers of an upper portion of the stack above the lower portion and the lines,
- forming channel-material-string structures that extend through first tiers and the second tiers in the upper portion to the lowest first tier in the lower portion;
- forming horizontally-elongated trenches into the stack that are individually between the immediately-laterally-adjacent memory-block regions and extend to the line there-between;
- removing the second sacrificial material of the lines through the trenches;
- and
- forming intervening material in the trenches and void-spaces left as a result of the removing of the second sacrificial material of the lines.
8 more elements
Dependencies are inferred from the claim text.