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: Memory circuitry comprising strings of memory cells comprises laterally-spaced memory blocks individually comprising 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 laterally-spaced memory blocks extend from the memory-array region into a stair-step region. Individual stairs in the stair-step region comprise one of the conductive tiers. Conductive vias are individually directly against conducting material that is in the one conductive tier in one of the individual stairs. Insulator material in the stair-step region is directly above the stairs. An insulative-material lining is circumferentially around and extends elevationally along individual of the conductive vias between the individual conductive vias and the insulator material.

Abstract: A microelectronic device is disclosed, comprising: a stack structure comprising vertically alternating conductive structures and insulating structures arranged in tiers, each of the tiers individually comprising one of the conductive structures and one of the insulating structures, the stack structure having blocks separated from one another by filled slot structures; a source tier structure underlying the stack structure and comprising: a merged conductive structure adjacent a first discrete conductive structure in a first direction; and a second discrete conductive structure in the first direction that is spaced apart from the merged conductive by the first discrete conductive structure; a first support contact structure on the first discrete conductive structure; and a subsequent support contact structure on the merged conductive structure and adjacent the first support contact in the first direction, wherein one of the filled slot structures is vertically directly above at least a portion of the merged co

Abstract: A microelectronic device comprises stack structure comprising an alternating sequence of conductive material and insulative material arranged in tiers, and having blocks separated by dielectric slot structures. Each of the blocks comprises a stadium structure, a filled trench overlying the stadium structure, support structures extending through the filled trench and tiers of the stack structure, and dielectric liner structures covering sidewalls of the support structures. The stadium structure comprises staircase structures each having steps comprising edges of the tiers of the stack structure. The filled trench comprises a dielectric material interposed between at least two additional dielectric materials. The dielectric liner structures comprise first protrusions at vertical positions of the dielectric material, and second protrusions at vertical positions of the conductive material of the tiers of the stack structure. The second protrusions have greater horizontal dimensions than the first protrusions.

Abstract: A microelectronic device comprises a stack structure comprising a vertically alternating sequence of conductive structures and insulative structures arranged in tiers, the stack structure divided into block structures separated from one another by slot structures, a staircase structure within the stack structure having steps comprising horizontal edges of the tiers, conductive contact structures in contact with the steps of the staircase structure, support pillar structures extending through the stack structure, and additional slot structures extending partially through the stack structure within one of the block structures, one of the additional slot structures extending between horizontally neighboring support pillar structures and closer to one of the horizontally neighboring support pillar structures than to an additional one of the horizontally neighboring support pillar structures. Related microelectronic devices, memory devices, and electronic systems are also described.

Abstract: Memory circuitry comprising strings of memory cells comprising laterally-spaced memory blocks individually comprise 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 laterally-spaced memory blocks extend from the memory-array region into a stair-step region. Individual stairs in the stair-step region comprise one of the conductive tiers and a riser. Conductive vias are individually directly against conductive material that is in the one conductive tier in one of the individual stairs. Individual of the conductive vias where directly against the conductive material are horizontally-longitudinally-elongated at an angle of 0° to 60° horizontally from the riser of the one individual stair. Other embodiments, including method, are disclosed.

Abstract: A microelectronic device comprises a stack structure comprising a vertically alternating sequence of conductive structures and insulative structures arranged in tiers, a staircase structure within the stack structure having steps comprising horizontal edges of the tiers, a first insulative material vertically overlying the staircase structure, conductive contact structures comprising a conductive material extending through the first insulative material and in contact with the steps of the staircase structure, and a second insulative material extending in a first horizontal direction between horizontally neighboring conductive contact structures and exhibiting one or more different properties than the first insulative material. Related microelectronic devices, electronic systems, and methods are also described.

Abstract: A microelectronic device comprises a stack structure comprising a vertically alternating sequence of conductive structures and insulative structures arranged in tiers, the stack structure divided into block structures separated from one another by slot structures, a staircase structure within the stack structure having steps comprising horizontal edges of the tiers, conductive contact structures in contact with the steps of the staircase structure, support pillar structures extending through the stack structure, and additional slot structures extending partially through the stack structure within one of the block structures, one of the additional slot structures extending between horizontally neighboring support pillar structures and closer to one of the horizontally neighboring support pillar structures than to an additional one of the horizontally neighboring support pillar structures. Related microelectronic devices, memory devices, and electronic systems are also described.

Abstract: Microelectronic devices include a stack structure having a vertically alternating sequence of insulative structures and conductive structures arranged in tiers. At least one stadium, of stadiums within the stack structure, comprise staircase(s) having steps provided by a group of the conductive structures. Step contacts extend to the steps of the staircase(s) of the at least one of the stadiums. Each conductive structure of the group of conductive structures has more than one of the step contacts in contact therewith at at least one of the steps of the staircase(s). Additional microelectronic devices are also disclosed, as are methods of fabrication and electronic systems.

Abstract: A microelectronic device, including a stack structure including alternating conductive structures and dielectric structures is disclosed. Memory pillars extend through the stack structure. Contacts are laterally adjacent to the memory pillars and extending through the stack structure. The contacts including active contacts and support contacts. The active contacts including a liner and a conductive material. The support contacts including the liner and a dielectric material. The conductive material of the active contacts is in electrical communication with the memory pillars. Methods and electronic systems are also disclosed.

Abstract: A microelectronic device comprises a stack structure, contact structures, and additional contact structures. The stack structure comprises a vertically alternating sequence of conductive material and insulative material arranged in tiers. The stack structure is divided into blocks each comprising a stadium structure including steps comprising horizontal ends of the tiers. The contact structures are within a horizontal area of the stadium structure and vertically extend through the stack structure. The additional contact structures are on at least some of the steps of the stadium structure and are coupled to the contact structures. Memory devices and electronic devices are also disclosed.

Abstract: A microelectronic device comprises a stack structure comprising a vertically alternating sequence of conductive structures and insulative structures arranged in tiers, a stair step structure within the stack structure and having steps comprising lateral edges of the tiers, pillar structures extending through the stack structure and the stair step structure and in contact with a source tier vertically underlying the stack structure, and conductive contact structures in contact with the steps of the staircase structure, the conductive contact structures individually comprising a first portion and a second portion vertically overlying the first portion, the second portion vertically above the pillar structures and having a greater lateral dimension than the first portion. Related microelectronic devices, memory devices, and electronic systems are also described.

Abstract: A microelectronic device comprises a stack structure, a stadium structure within the stack structure, a source tier underlying the stack structure, and a masking structure. The stack structure has tiers each comprising a conductive structure and an insulating structure. The stadium structure comprises a forward staircase structure, a reverse staircase structure, and a central region horizontally interposed between the forward staircase structure and the reverse staircase structure. The source tier comprises discrete conductive structures within horizontal boundaries of the central region of the stadium structure and horizontally separated from one another by dielectric material. The masking structure is confined within the horizontal boundaries of the central region of the stadium structure and is vertically interposed between the source tier and the stack structure.

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 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: Some embodiments include an integrated assembly having a memory array region which includes channel material pillars extending through a stack of alternating conductive and insulative levels. A second region is adjacent the memory array region. A conductive expanse is within the memory array region and electrically coupled with the channel material of the channel material pillars. A panel extends across the memory array region and the second region. The panel separates one memory block region from another. The panel has a first portion over the conductive expanse, and has a second portion adjacent the first portion. The panel has a bottom surface. A first segment of the bottom surface is adjacent an upper surface of the conductive expanse. A segment of the bottom surface within the second portion is elevationally offset relative to the first segment. Some embodiments include methods of forming integrated assemblies.

Abstract: A microelectronic device comprises a stack structure comprising insulative structures vertically interleaved with conductive structures, first support pillar structures vertically extending through the stack structure in a first staircase region including steps defined at edges of tiers of the insulative structures and conductive structures, and second support pillar structures vertically extending through the stack structure in a second staircase region including additional steps defined at edges of additional tiers of the insulative structures and conductive structures, the second support pillar structures having a smaller cross-sectional area than the first support pillar structures. Related memory devices, electronic systems, and methods are also described.

Abstract: An electronic device comprising first blocks and second blocks of an array comprising memory cells. The memory cells in the first and second blocks comprise memory pillars extending through a stack. The memory pillars comprise a charge blocking material laterally adjacent to the stack, a storage nitride material laterally adjacent to the charge blocking material, a tunnel dielectric material laterally adjacent to the storage nitride material, a channel material laterally adjacent to the tunnel dielectric material, and a fill material between opposing sides of the channel material. One or more of the storage nitride material and the tunnel dielectric material in the first blocks differ in thickness or in material composition from one or more of the storage nitride material and the tunnel dielectric material in the second blocks. Additional electronic devices are disclosed, as are methods of forming an electronic device and related systems.

Abstract: A microelectronic device comprises a stack structure comprising vertically alternating conductive structures and insulating structures arranged in tiers, the tiers individually comprising one of the conductive structures and one of the insulating structures, a staircase structure within the stack structure and having steps comprising edges of at least some of the tiers, conductive contact structures on the steps of the staircase structure, support pillar structures laterally offset in at least a first direction from the conductive contact structures and extending through the stack structure, and bridge structures comprising an electrically insulating material extending vertically through at least a portion of the stack structure and between at least some adjacent support pillar structures of the support pillar structures. Related memory devices, electronic systems, and methods are also described.

Abstract: Integrated circuitry comprises vertical conductive vias individually having a lower portion thereof that is directly against conductor material of islands. The islands comprise multiple different composition materials directly above the conductor material. Apart from the conductive vias, the islands individually comprise at least one of (a), (b), or (c), where: (a): a top material that is of different composition from all material that is vertically between the top material and the conductor material; (b): the top material having its top surface in a vertical cross-section extending laterally-outward beyond two opposing laterally-outermost edges of a top surface of the material that is immediately directly below the top material; and (c): is of different composition from that of an upper portion of the conductor material and including a portion thereof that is elevationally coincident with the conductor material or that is directly against the conductor material.