Electronic devices including stair step structures, and related memory devices, systems, and methods

A method of forming an electronic device, the method comprising:

• forming pillars in a stack comprising alternating first materials and second materials within an array region;
• forming an upper insulative material over the stack;
• forming stair step structures in the stack within a staircase region laterally adjacent to the array region;
• forming support pillars comprising a liner and a fill material within the staircase region;
• forming support structures extending vertically through the stack within one or more of the array region and the staircase region;
• forming slots extending through the stack, the slots positioned relatively closer to the support structures than to the support pillars;
• and
• forming conductive contacts on individual steps of the stair step structures, upper surfaces of each of the upper insulative material, the support pillars, the support structures, and the conductive contacts substantially coplanar with one another.

A memory device, comprising:

• strings of memory cells within an array region and extending vertically through a stack of alternating dielectric materials and conductive materials;
• at least one stair step structure within a staircase region of the stack, the at least one stair step structure including steps defined by horizontal ends of the conductive materials;
• conductive contacts physically contacting the steps of the at least one stair step structure;
• first support structures extending vertically through the stack within the at least one stair step structure, at least some of the first support structures comprising a conductive material;
• and
• second support structures extending vertically through the stack within one or more of the array region and the staircase region and external to the at least one stair step structure, each of the second support structures comprising an insulative material without comprising a conductive material, and each of the second support structures exhibiting a smaller lateral cross-sectional area than each of the first support structures.

A system, comprising:

• a processor operably coupled to an input device and an output device;
• and
• one or more electronic devices operably coupled to the processor, the one or more electronic devices comprising:
• a stack comprising tiers of alternating conductive structures and insulating structures;
• stadium structures within the stack and comprising opposing stair step structures each individually including steps defined by edges of the tiers;
• contact structures on the steps of the opposing stair step structures;
• slots extending through the stack;
• and
• support structures between the slots and the contact structures and extending vertically through the stack, the support structures exhibiting oblong cross-sectional shapes horizontally aligned with the conductive structures without being located between neighboring conductive contacts.