Abstract: A microelectronic device comprises pillar structures comprising semiconductive material, contact structures in physical contact with upper portions of the pillar structures, and conductive structures over and in physical contact with the contact structures. Each of the conductive structures comprises an upper portion having a first width, and a lower portion vertically interposed between the upper portion and the contact structures. The lower portion has a tapered profile defining additional widths varying from a second width less than the first width at an uppermost boundary of the lower portion to a third width less than the second width at a lowermost boundary of the lower portion. Memory devices, electronic systems, and methods of forming microelectronic devices are also described.

Abstract: Some embodiments include an integrated assembly having a conductive expanse over conductive nodes. The conductive nodes include a first composition. A bottom surface of the conductive expanse includes a second composition which is different composition than the first composition. A stack is over the conductive expanse. The stack includes alternating first and second levels. Pillar structures extend vertically through the stack. Each of the pillar structures includes a post of conductive material laterally surrounded by an insulative liner. At least one of the posts extends through the conductive expanse to directly contact one of the conductive nodes. Some embodiments include methods of forming integrated assemblies.

Abstract: Integrated circuitry comprises two three-dimensional (3D) array regions individually comprising tiers of electronic components. A stair-step region is between the two 3D-array regions. First stair-step structures alternate with second stair-step structures along a first direction within the stair-step region. The first stair-step structures individually comprise two opposing first flights of stairs in a first vertical cross-section along the first direction. The stairs in the first flights each have multiple different-depth treads in a second vertical cross-section that is along a second direction that is orthogonal to the first direction. The second stair-step structures individually comprise two opposing second flights of stairs in the first vertical cross-section. The stairs in the second flights each have only a single one tread along the second direction. Other embodiments, including method, are disclosed.

Abstract: Some embodiments include an integrated assembly having a first deck, a second deck over the first deck, and a third deck over the second deck. The first deck has first conductive levels disposed one atop another. The second deck has second conductive levels disposed one atop another. The third deck has third conductive levels disposed one atop another. A first staircase region extends to the first and second conductive levels, and passes through the third conductive levels. A second staircase region extends to the third conductive levels and not to the first and second conductive levels. Some embodiments include methods of forming 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. Operative channel-material strings of memory cells extend through the insulative tiers and the conductive tiers. The operative channel-material strings in the laterally-spaced memory blocks comprise part of a memory plane. An elevationally-extending wall is in the memory plane laterally-between immediately-laterally-adjacent of the memory blocks and that completely encircles an island that is laterally-between immediately-laterally-adjacent of the memory blocks in the memory plane. Other embodiments, including method are disclosed.

Abstract: A microelectronic device includes a stack structure having tiers each including conductive material vertically neighboring insulative material and conductive contact structures. The stack structure is divided into blocks horizontally extending in parallel in a first direction and separated from one another in a second direction orthogonal to the first direction by insulative slot structures. At least one of the blocks includes a lower stadium structure having steps including edges of some of the tiers, and an upper stadium structure vertically overlying the lower stadium structure and having additional steps including edges of some other of the tiers vertically overlying the some of the tiers. The additional steps have greater tread widths in the first direction than the steps. Conductive contact structures are in contact with the additional steps of the upper stadium structure of the at least one of the blocks. Memory devices and electronic systems are also described.

Abstract: A microelectronic device comprises a stack structure comprising a vertically alternating sequence of conductive material and insulative material arranged in tiers. The stack structure has blocks separated from one another by first dielectric slot structures. Each of the blocks comprises two crest regions, a stadium structure interposed between the two crest regions in a first horizontal direction and comprising opposing staircase structures each having steps comprising edges of the tiers of the stack structure, and two bridge regions neighboring opposing sides of the stadium structure in a second horizontal direction orthogonal to the first horizontal direction and having upper surfaces substantially coplanar with upper surfaces of the two crest regions. At least one second dielectric slot structure is within horizontal boundaries of the stadium structure in the first horizontal direction and partially vertically extends through and segmenting each of the two bridge regions.

Abstract: A microelectronic device comprises a stack structure comprising alternating conductive structures and insulative structures arranged in tiers, the tiers individually comprising one of the conductive structures and one of the insulative structures, first support pillar structures extending through the stack structure within a first region of the microelectronic device, the first support pillar structures electrically isolated from a source structure underlying the stack structure, second support pillar structures extending through the stack structure within a second region of the microelectronic device, the second support pillar structures comprising an electrically conductive material in electrical communication with the source structure, and bridge structures extending between at least some neighboring first support pillar structures of the first support pillar structures. Related memory devices, electronic systems, and methods are also described.

Abstract: A microelectronic device comprises pillar structures comprising semiconductive material, contact structures in physical contact with upper portions of the pillar structures, and conductive structures over and in physical contact with the contact structures. Each of the conductive structures comprises an upper portion having a first width, and a lower portion vertically interposed between the upper portion and the contact structures. The lower portion has a tapered profile defining additional widths varying from a second width less than the first width at an uppermost boundary of the lower portion to a third width less than the second width at a lowermost boundary of the lower portion. Memory devices, electronic systems, and methods of forming microelectronic devices are also described.

Abstract: A device comprises an array of elevationally-extending transistors and a circuit structure adjacent and electrically coupled to the elevationally-extending transistors of the array. The circuit structure comprises a stair step structure comprising vertically-alternating tiers comprising conductive steps that are at least partially elevationally separated from one another by insulative material. Operative conductive vias individually extend elevationally through one of the conductive steps at least to a bottom of the vertically-alternating tiers and individually electrically couple to an electronic component below the vertically-alternating tiers. Dummy structures individually extend elevationally through one of the conductive steps at least to the bottom of the vertically-alternating tiers. Methods are also disclosed.

Abstract: Some embodiments include a method of forming an integrated assembly. Laterally alternating first and second sacrificial materials are formed over a conductive structure, and then a stack of vertically alternating first and second levels is formed over the sacrificial materials. The first levels include first material and the second levels include insulative second material. Channel-material-openings are formed to extend through the stack and through at least some of the strips. Channel-material-pillars are formed within the channel-material-openings. Slits are formed to extend through the stack and through the sacrificial materials. The first sacrificial material is replaced with first conductive material and then the second sacrificial material is replaced with second conductive material. At least some of the first material of the stack is replaced with third 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. Operative channel-material strings of memory cells extend through the insulative tiers and the conductive tiers. The operative channel-material strings in the laterally-spaced memory blocks comprise part of a memory plane. An elevationally-extending wall is in the memory plane laterally-between immediately-laterally-adjacent of the memory blocks and that completely encircles an island that is laterally-between immediately-laterally-adjacent of the memory blocks in the memory plane. Other embodiments, including method are disclosed.

Abstract: A microelectronic device includes a stack structure comprising a vertically alternating sequence of insulative structures and conductive structures arranged in tiers. At least one slit region divides the stack structure into blocks. Each block comprises an array of active pillars. Along the at least one slit region is a horizontally alternating sequence of slit structure segments and support pillar structures. The slit structure segments and the support pillar structures each extend vertically through the stack structure. Additional microelectronic devices are also disclosed as are related methods and electronic systems.

Abstract: Microelectronic devices include a stack with a vertically alternating sequence of insulative and conductive structures arranged in tiers. A staircased stadium within the stack comprises steps at different tier elevations of a group of the tiers. Treads of the steps are each provided by an upper surface area of one of the conductive structures within the group of the tiers and by an upper surface area of a metal oxide region extending through the one of the conductive structures. A pair of conductive contact structures extends to one of the steps. A first conductive contact structure of the pair terminates at the tread of the step, within the area of the conductive structure. A second conductive contact structure of the pair extends through the tread of the step, within the upper surface area of the metal oxide region. Related fabrication methods and electronic systems are also disclosed.

Abstract: Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes memory cells located on tiers; control gates for the memory cells and located on respective tiers; a dielectric structure over the control gates; a first conductive contact formed in the dielectric structure and contacting a first control gate, the first conductive contact having a first length; and a second conductive contact formed in the dielectric structure and contacting the second control gate, the second conductive contact having a second length unequal to the first length, wherein the second conductive contact includes a first portion and a second portion, the second portion is between the first portion and the second control gate, the first portion including a first region having a first width, the second portion including a second region having a second width, and the second width being greater than the first width.

Abstract: A memory array comprises strings of memory cells. The memory array comprises laterally-spaced memory blocks that individually comprise a vertical stack comprising alternating insulative tiers and conductive tiers directly above a conductor tier. Channel-material strings of memory cells extend through the insulative tiers and the conductive tiers. The channel material of the channel-material strings directly electrically couples to conductor material of the conductor tier. Individual ones of the channel-material strings in a vertical cross-section comprise an external jog surface that is above the conductor tier and an internal jog surface that is in the conductor tier. Other aspects, including methods, are disclosed.

Abstract: A method of forming a microelectronic device comprises forming a microelectronic device structure. The microelectronic device structure comprises a stack structure comprising insulative structures and additional insulative structures vertically alternating with the insulative structures, a dielectric structure vertically extending partially through the stack structure, and a dielectric material vertically overlying and horizontally extending across the stack structure and the dielectric structure. Portions of at least the dielectric material and the dielectric structure are removed to form a trench vertically overlying and at least partially horizontally overlapping a remaining portion of the dielectric structure. The trench is substantially filled with additional dielectric material. Microelectronic devices, memory devices, and electronic systems are also described.

Abstract: Some embodiments include a method of forming an integrated assembly. Laterally alternating first and second sacrificial materials are formed over a conductive structure, and then a stack of vertically alternating first and second levels is formed over the sacrificial materials. The first levels include first material and the second levels include insulative second material. Channel-material-openings are formed to extend through the stack and through at least some of the strips. Channel-material-pillars are formed within the channel-material-openings. Slits are formed to extend through the stack and through the sacrificial materials. The first sacrificial material is replaced with first conductive material and then the second sacrificial material is replaced with second conductive material. At least some of the first material of the stack is replaced with third conductive material. Some embodiments include integrated assemblies.

Abstract: Some embodiments include an integrated assembly having a conductive expanse over conductive nodes. The conductive nodes include a first composition. A bottom surface of the conductive expanse includes a second composition which is different composition than the first composition. A stack is over the conductive expanse. The stack includes alternating first and second levels. Pillar structures extend vertically through the stack. Each of the pillar structures includes a post of conductive material laterally surrounded by an insulative liner. At least one of the posts extends through the conductive expanse to directly contact one of the conductive nodes. Some embodiments include methods of forming integrated assemblies.

Abstract: A microelectronic device comprises a stack structure comprising blocks each including a vertically alternating sequence of conductive material and insulative material arranged in tiers, at least one of the blocks comprising: a memory array region having vertically extending strings of memory cells within a horizontal area thereof; and a staircase region horizontally neighboring the memory array region. The staircase structure has steps comprising horizontal ends of the tiers; and a crest sub-region horizontally interposed between the staircase structure and the memory array region. A masking structure overlies the stack structure and has a different material composition than each of the conductive material and the insulative material. Filled slot structures are interposed between the blocks of the stack structure, at least one of the filled slot structures comprises at least one fill material that has an uppermost boundary vertically underlying an uppermost boundary of the masking structure.