Abstract: Integrated circuitry comprising a memory array comprises strings of memory cells comprising laterally-spaced memory blocks individually comprising a first vertical stack comprising alternating insulative tiers and conductive tiers above a conductor tier. Strings of memory cells comprise channel-material strings that extend through the insulative tiers and the conductive tiers. The channel-material strings directly electrically couple with conductor material of the conductor tier. The conductive tiers individually comprise a horizontally-elongated conductive line. A second vertical stack is aside the first vertical stack. The second vertical stack comprises an upper portion and a lower portion. The upper portion comprises vertically-alternating first insulating tiers and second insulating tiers that are of different insulative compositions relative one another.

Abstract: Some embodiments include an integrated structure having a stack of memory cell levels. A pair of channel-material-pillars extend through the stack. A source structure is under the stack. The source structure includes a portion having an upper region, a lower region, and an intermediate region between the upper and lower regions. The upper and lower regions have a same composition and join to one another at edge locations. The intermediate region has a different composition than the upper and lower regions. The edge locations are directly against the channel material of the channel-material-pillars. Some embodiments include methods of forming an integrated assembly.

Abstract: A microelectronic device may include a source structure and a stack structure. The stack structure may include a vertically alternating sequence of insulative structures and conductive structures. Filled slits may extend through the stack structure and into the source structure, the slits dividing the stack structure into multiple blocks. Memory cell pillars may extend through the stack structure and into the source structure, the memory cell pillars and the filled slits terminated at substantially the same depth within the source structure as one another.

Abstract: A method used in forming a memory array comprising strings of memory cells comprises forming a lower portion of a stack that will comprise vertically-alternating first tiers and second tiers. The stack comprises laterally-spaced memory-block regions. Material of the first tiers is of different composition from material of the second tiers. The lower portion comprises an upper second tier comprising insulative material. The vertically-alternating first tiers and second tiers of an upper portion of the stack are formed above the lower portion. Channel-material strings are formed that extend through the upper portion to the lower portion. Horizontally-elongated lines are formed in the upper second tier longitudinally-along opposing lateral edges of the memory-block regions. Material of the lines is of different composition from that of the insulative material in the upper second tier that is laterally-between the lines.

Abstract: Integrated circuitry comprising a memory array comprises strings of memory cells comprising laterally-spaced memory blocks individually comprising a first vertical stack comprising alternating insulative tiers and conductive tiers above a conductor tier. Strings of memory cells comprise channel-material strings that extend through the insulative tiers and the conductive tiers. The channel-material strings directly electrically couple with conductor material of the conductor tier. The conductive tiers individually comprise a horizontally-elongated conductive line. A second vertical stack is aside the first vertical stack. The second vertical stack comprises an upper portion and a lower portion. The upper portion comprises vertically-alternating first insulating tiers and second insulating tiers that are of different insulative compositions relative one another.

Abstract: A variety of applications can include memory devices designed to provide enhanced gate-induced-drain-leakage (GIDL) current during memory erase operations. The enhanced operation can be provided by enhancing the electric field in the channel structures of select gate transistors to strings of memory cells at segmented drains of the select gate transistors. The segmented drains can have conductive fins integrated with the transistor channel structure and extending vertically from a top border of the transistor channel structure, where the conductive fins are separated from each other by non-conductive regions on the top border. The segmented drain can include portions extending downward below the top border. The transistor channel structures can be integrated with the channel structures of the pillars forming the strings of memory cells. Additional devices, systems, and methods are discussed.

Abstract: A method used in forming a memory array comprises forming a substrate comprising a conductor tier comprising an upper conductor material and a lower conductor material, and a stack comprising vertically-alternating first tiers and second tiers above the conductor tier. Horizontally-elongated trenches are formed through the stack to the upper conductor material and the lower conductor material. At least one of the upper and lower conductor materials have an exposed catalytic surface in the trenches. Metal material is electrolessly deposited onto the catalytic surface to cover the upper conductor material and the lower conductor material within the trenches. Channel-material strings of memory cells are formed and extend through the second tiers and the first tiers. Other embodiments, including structure independent of method, are disclosed.

Abstract: Some embodiments include an integrated structure having a stack of memory cell levels. A pair of channel-material-pillars extend through the stack. A source structure is under the stack. The source structure includes a portion having an upper region, a lower region, and an intermediate region between the upper and lower regions. The upper and lower regions have a same composition and join to one another at edge locations. The intermediate region has a different composition than the upper and lower regions. The edge locations are directly against the channel material of the channel-material-pillars. Some embodiments include methods of forming an integrated assembly.

Abstract: A microelectronic device may include a source structure and a stack structure. The stack structure may include a vertically alternating sequence of insulative structures and conductive structures. Filled slits may extend through the stack structure and into the source structure, the slits dividing the stack structure into multiple blocks. Memory cell pillars may extend through the stack structure and into the source structure, the memory cell pillars and the filled slits terminated at substantially the same depth within the source structure as one another.

Abstract: Memory circuitry comprising strings of memory cells comprises a stack comprising vertically-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 comprise a first silicon oxide. The insulative tiers and the conductive tiers extend from the memory-array region into a stair-step region. The stair-step region comprises a flight of stairs. The stairs individually comprise a tread comprising conductive material of one of the conductive tiers. Individual of the treads comprise a second silicon oxide directly above the conductive material of the one conductive tier. The second silicon oxide comprises one or more of boron and phosphorus at a total concentration that is greater than a total concentration of one or more of boron and phosphorus, if any, that is in the first silicon oxide that is directly below the second silicon oxide.

Abstract: Memory circuitry comprises a stack comprising vertically-alternating insulative tiers and conductive tiers. The stack comprises laterally-spaced memory blocks. The memory blocks individually comprise sub-blocks in an upper portion thereof. Strings of memory cells are included and that comprise channel-material strings that extend through the insulative tiers and the conductive tiers in the memory blocks. A conductive-material tier is included and that comprises conductive material in the upper portions. The conductive material extends downwardly from the conductive-material tier to below the conductive-material tier. Sub-block trenches in the upper portions are individually between immediately-laterally-adjacent of the sub-blocks and extend through the conductive-material tier. Select gates of select-gate transistors are in individual of the sub-blocks operatively alongside channel material of the select-gate transistors.

Abstract: Some embodiments include methods of forming integrated assemblies. A conductive structure is formed to include a semiconductor-containing material over a metal-containing material. An opening is formed to extend into the conductive structure. A conductive material is formed along a bottom of the opening. A stack of alternating first and second materials is formed over the conductive structure either before or after forming the conductive material. Insulative material and/or channel material is formed to extend through the stack to contact the conductive material. Some embodiments include integrated assemblies.

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 above a conductor tier. Strings of memory cells comprise channel-material strings that extend through the insulative tiers and the conductive tiers. The channel-material strings directly electrically couple with conductor material of the conductor tier by conducting material that is in a lowest of the conductive tiers and that is directly against multiple of the channel-material strings. A through-array-via (TAV) region comprises TAVs that individually extend through the lowest conductive tier and into the conductor tier. Individual of the TAVs in the lowest conductive tier comprise a conductive core having an annulus circumferentially there-about. The annulus has dopant therein at a total dopant concentration of 0.01 to 30 atomic percent.

Abstract: A method used in forming a memory array comprising strings of memory cells comprises forming a stack comprising vertically-alternating first tiers and second tiers above a substrate. Horizontally-elongated trenches are formed into the stack to form laterally-spaced memory-block regions. Catalytic material is formed in a bottom region of individual of the trenches. Metal material is electrolessly deposited onto a catalytic surface of the catalytic material to individually fill at least a majority of remaining volume of the individual trenches. Channel-material strings are formed and extend through the first tiers and the second tiers. Other embodiments, including structure independent of method, are disclosed.

Abstract: Electronic devices comprising a doped dielectric material adjacent to a source contact, tiers of alternating conductive materials and dielectric materials adjacent to the doped dielectric material, and pillars extending through the tiers, the doped dielectric material, and the source contact and into the source stack. Related methods and electronic systems are also disclosed.

Abstract: A microelectronic device includes a stack structure, a staircase structure, conductive pad structures, and conductive contact structures. The stack structure includes vertically alternating conductive structures and insulating structures arranged in tiers. Each of the tiers individually includes one of the conductive structures and one of the insulating structures. The staircase structure has steps made up of edges of at least some of the tiers of the stack structure. The conductive pad structures are on the steps of the staircase structure and include beta phase tungsten. The conductive contact structures are on the conductive pad structures. Memory devices, electronic systems, and methods of forming microelectronic devices are also described.

Abstract: A method used in forming a conductive via of integrated circuitry comprises forming a lining laterally over sidewalls of an elevationally-elongated opening. The lining comprises elemental-form silicon. The elemental-form silicon of an uppermost portion of the lining is ion implanted in the elevationally-elongated opening. The ion-implanted elemental-form silicon of the uppermost portion of the lining is etched selectively relative to the elemental-form silicon of a lower portion of the lining below the uppermost portion that was not subjected to said ion implanting. The elemental-form silicon of the lower portion of the lining is reacted with a metal halide to form elemental-form metal in a lower portion of the elevationally-elongated opening that is the metal from the metal halide. Conductive material in the elevationally-elongated opening is formed atop and directly against the elemental-form metal. Other embodiments, including structure independent of method, are disclosed.

Abstract: A microelectronic device comprises a stack structure, a staircase structure, a first liner material, a liner structure, conductive contact structures, and barrier structures. The stack structure comprises vertically alternating conductive structures and insulative structures arranged in tiers. Each of the tiers individually comprises one of the conductive structures and one of the insulative structures. The staircase structure has steps comprising edges of at least some of the tiers of the stack structure. The first liner material is on the steps of the staircase structure, and the liner structure on the first liner material. The conductive contact structures extend through the first liner material and the liner structure and to the conductive structures of the stack structure. The barrier structures are between the conductive contact structures and the liner structure vertically span substantially the same tiers of the stack structure as the liner structure.

Abstract: Electronic devices comprising a doped dielectric material adjacent to a source contact, tiers of alternating conductive materials and dielectric materials adjacent to the doped dielectric material, and pillars extending through the tiers, the doped dielectric material, and the source contact and into the source stack. Related methods and electronic systems are also disclosed.

Abstract: Methods, systems, and devices for access circuitry structures for three-dimensional (3D) memory arrays are described. A memory device may include levels of memory cells over a substrate. To support accessing memory cells at respective levels, the memory device may include a conductive pillar extending through the levels of memory cells and coupled with one or more memory cells at respective levels of memory cells. The memory device may include a bit line and a contact that is configured to couple the bit line with the conductive pillar. The conductive pillar may be formed such that it extends into a portion of the contact, and a contact resistance between the conductive pillar and the bit line may be based on the conductive pillar extending into the portion of the contact.