Microelectronic devices including slot structures and additional slot structures, and related memory devices and electronic systems

A memory device, comprising:

• a stack structure comprising a vertically alternating sequence of conductive material and insulative material arranged in tiers, the stack structure including:
• a staircase structure comprising steps defined by edges of at least some of the tiers;
• and
• a crest region horizontally neighboring the staircase structure in a first direction;
• strings of memory cells vertically extending through the stack structure;
• support pillar structures vertically extending through the stack structure and arranged in rows, each row of the support pillar structures horizontally extending in the first direction from the staircase structure to the crest region;
• block isolation structures horizontally extending in the first direction and dividing the stack structure into blocks;
• sub-block isolation structures horizontally extending in the first direction and dividing respective ones of the blocks into sub-blocks, the sub-block isolation structures within the respective ones of the blocks including:
• a first sub-block isolation structure;
• and
• a second sub-block isolation structure positioned between the first sub-block isolation structure and a nearest one of the block isolation structures in a second direction orthogonal to the first direction, the second sub-block isolation more proximate to the first sub-block isolation structure than to the nearest one of the block isolation structures.

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 comprising a vertically alternating sequence of conductive material and insulative material arranged in tiers;
• slot structures horizontally extending in a first direction and segmenting the stack structure into block structures;
• and
• additional slot structures horizontally extending in the first direction and partially defining sub-block regions of the block structures, the sub-block regions of respective ones of the block structures comprising:
• a first sub-block region;
• and
• a second sub-block region spaced apart from the first sub-block region in a second direction orthogonal to the first direction, the first sub-block region more proximate to one of the slot structures than the second sub-block region and having a greater width in the second direction than the second sub-block region;
• and
• support pillar structures arranged in rows within the sub-block regions of the block structures.