A microelectronic device comprises a first microelectronic device structure and a second microelectronic device structure attached to the first microelectronic device structure. The first microelectronic device structure comprises a memory array region comprising a stack structure comprising levels of conductive structures vertically alternating with levels of insulative structures, and staircase structures at lateral ends of the stack structure. The memory array region further comprises vertical stacks of memory cells, at least one of the vertical stacks of memory cells comprising stacked capacitor structures, each stacked capacitor structure comprising capacitor structures vertically spaced from each other by at least a level of the levels of insulative structures, transistor structures, each transistor structure operably coupled to a capacitor structure and to one of the conductive structures of the levels of conductive structures, and a conductive pillar structure vertically extending through the transistor structures.