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
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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.
Claims24
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 on a substrate, the stack comprising laterally-spaced memory-block regions, material of the first tiers being of different composition from material of the second tiers;
- forming pillars in the lower portion that are individually horizontally-located where individual channel-material-string structures will be formed, the pillars comprising sacrificial material;
- forming the vertically-alternating first tiers and second tiers of an upper portion of the stack above the lower portion and the pillars;
- forming channel openings into the stack that individually extend to individual of the pillars;
- removing the sacrificial material of the pillars through the channel openings to extend the channel openings deeper into the stack;
- forming channel-material-string structures in the extended channel openings and in void-space therein resulting from said removing;
- the channel-material-string structures individually comprising an upper portion above and joined with a lower portion, individual of the channel-material-string structures comprising at least one external jog surface in a vertical cross-section where the upper and lower portions join;
- and
- the at least one external jog surface being more than 10° from horizontal.
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 pillars in the lowest first tier that are individually horizontally-located where individual channel-material-string structures will be formed, the pillars 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 pillars;
- forming channel openings into the stack that individually extend to individual of the pillars;
- removing the second sacrificial material of the pillars through the channel openings to extend the channel openings deeper into the stack;
- forming channel-material-string structures in the extended channel openings and in void-space therein resulting from said removing;
- forming horizontally-elongated trenches into the stack that are individually between immediately-laterally-adjacent of the memory-block regions and extend to the first sacrificial material in the lowest first tier;
- isotropically etching the first sacrificial material from the lowest first tier through the trenches;
- after the isotropically etching, forming conductive material in the lowest first tier that directly electrically couples together the channel material of the individual channel-material-string structures and the conductor material of the conductor tier;
- and
- the channel-material-string structures individually comprising an upper portion above and joined with a lower portion, individual of the channel-material-string structures comprising at least one external jog surface in a vertical cross-section where the upper and lower portions join;
- and
- the at least one external jog surface being more than 10° from horizontal.
Dependencies are inferred from the claim text.