Methods of forming microelectronic devices, and related microelectronic devices, memory devices, and electronic systems

A method of forming a microelectronic device, comprising:

• forming a preliminary stack structure comprising a vertically alternating sequence of sacrificial material and insulative material arranged in tiers, the preliminary stack structure further comprising rows of stadium structures each comprising:
• at least two of the stadium structures neighboring one another in a first horizontal direction and each comprising opposing staircase structures having steps comprising edges of the tiers of the preliminary stack structure;
• forming at least two filled trenches vertically over and within horizontal boundaries of the at least two of the stadium structures of each of the rows of stadium structures, each of the at least two filled trenches comprising:
• a dielectric liner material on surfaces of the preliminary stack structure;
• and
• dielectric structures on the dielectric liner material and substantially confined within horizontal areas of the steps of the opposing staircase structures of one of the at least two of the stadium structures;
• dividing the preliminary stack structure into blocks separated from one another by slots, each of the blocks comprising:
• one of the rows of stadium structures;
• at least one crest region interposed between the at least two of the stadium structures of the one of the rows of stadium structures in the first horizontal direction;
• and
• bridge regions integral and continuous with the at least one crest region and neighboring the at least two of the stadium structures in a second horizontal direction orthogonal to the first horizontal direction;
• and
• replacing the sacrificial material of the preliminary stack structure with conductive material by way of the slots.

A memory device, comprising:

• a stack structure comprising tiers each comprising a conductive material and an insulative material vertically neighboring the conductive material, the stack structure divided into blocks extending in parallel in a first direction and separated from one another in a second direction by dielectric slot structures, each of the blocks comprising:
• a stadium structure comprising opposing staircase structures individually having steps comprising horizontal ends of at least some the tiers of the stack structure;
• first elevated regions neighboring opposing ends of the stadium structure in the first direction;
• and
• second elevated regions neighboring opposing sides of the stadium structure in the second direction, uppermost surfaces of the second elevated regions substantially coplanar with uppermost surfaces of the first elevated regions;
• filled trenches within the blocks of the stack structure, each of the filled trenches vertically over and within a horizontal area of the stadium structure of one of the blocks of the stack structure and comprising:
• a dielectric liner material on surfaces of the stadium structure, the first elevated regions, and the second elevated regions;
• dielectric structures on the dielectric liner material and substantially confined within horizontal boundaries of the steps of the stadium structure;
• and
• a dielectric fill material over the dielectric structures and the dielectric liner material;
• and
• strings of memory cells vertically extending through a portion of each of the blocks neighboring the stadium structure in the first direction.

An electronic system, comprising:

• an input device;
• an output device;
• a processor device operably coupled to the input device and the output device;
• and
• a memory device operably coupled to the processor device and comprising at least one microelectronic device structure comprising:
• a stack structure having a vertically alternating sequence of conductive material and insulative material arranged in tiers, the stack structure comprising at least two blocks separated from one another by at least one dielectric structure, each of the at least two blocks comprising:
• two elevated regions;
• a stadium structure interposed between the two elevated regions in a first horizontal direction and comprising staircase structures opposing one another in the first horizontal direction, the staircase structures each having steps comprising edges of the tiers of the stack structure;
• and
• two additional elevated regions neighboring opposing sides of the stadium structure in a second horizontal direction perpendicular to the first horizontal direction;
• filled trenches over and within horizontal boundaries of the at least two blocks of the stack structure, each of filled trenches comprising:
• a dielectric liner material on surfaces of the stadium structure, the two elevated regions, and the two additional elevated regions of one of the at least two blocks of the stack structure;
• dielectric structures on horizontally extending surfaces of the dielectric liner material and omitted from vertically extended surfaces of the dielectric liner material;
• and
• a dielectric fill material over the dielectric structures and the dielectric liner material;
• and
• conductive contact structures vertically extending completely through the filled trenches.