US 2026/0040541 A1 · Memory Circuitry Comprising Strings of Memory Cells and Method Used in Forming a Memory Array Comprising Strings of Memory Cells

Abstract

Memory circuitry comprising strings of memory cells comprising memory blocks individually comprises a vertical stack comprising alternating insulative tiers and conductive tiers. Channel-material strings of memory cells extend through the insulative tiers and the conductive tiers in a memory-array region. The insulative tiers and the conductive tiers of the memory blocks extend from the memory-array region into a stair-step region. Individual of the memory blocks in the stair-step region comprise a flight of operative stairs. Individual of the operative stairs comprise one of the conductive tiers. At least some immediately-laterally-adjacent of the individual memory blocks in the stair-step region have their flights of operative stairs laterally-separated by a stack comprising two vertically-alternating different-composition insulative materials. Other embodiments, including method, are disclosed.

Claims16

Dependent claims

A method used in forming a memory array comprising strings of memory cells, comprising:
forming a stack comprising vertically-alternating first tiers and second tiers comprising different composition first insulative material and second insulative material, respectively, on a substrate;
the stack comprising memory-block regions extending from a memory-array region into a stair-step region along a first direction;
forming a stair-step structure comprising the first and second tiers in the stair-step region across and that spans between two immediately-adjacent of the memory-block regions along a second direction;
forming trenches along the first direction that are individually laterally between immediately-adjacent of the memory blocks in the memory-array region, two of the trenches in the first direction extending completely across the stair-step structure laterally-outward of opposing sides of the stair-step structure, one of the trenches being laterally between the two trenches and not extending completely across the stair-step structure in the first direction;
etching the first insulative material selectively relative to the second insulative material through the two and one trenches to leave a stack of the first and second insulative materials in the stair-step structure that is laterally-spaced from the two trenches;
after the etching, forming conductive material in the first tiers through the one and two trenches;
forming a wall in individual of the one and two trenches;
and
forming channel material strings that extend through the first tiers and the second tiers in the memory-block regions.

7 more elements

Memory Circuitry Comprising Strings of Memory Cells and Method Used in Forming a Memory Array Comprising Strings of Memory Cells

Life of this patent

Memory Circuitry Comprising Strings of Memory Cells and Method Used in Forming a Memory Array Comprising Strings of Memory Cells

Life of this patent

Abstract

Claims16