Microelectronic devices including staircase structures, and related memory devices and electronic systems

A memory device, comprising:

• a stack structure comprising tiers each comprising alpha phase tungsten material and insulative material vertically neighboring the alpha phase tungsten material;
• strings of memory cells vertically extending through the tiers of the stack structure;
• a staircase structure horizontally offset from an array of the strings of memory cells and having steps comprising edges of at least some of the tiers of the stack structure;
• beta phase tungsten pad structures directly physically contacting the steps of the staircase structure, each of the beta phase tungsten pad structures having a horizontal center spaced apart from a horizontal center of one of the steps directly vertically thereunder;
• and
• conductive contacts directly physically contacting the beta phase tungsten pad structures;
• access lines coupled to the conductive contacts;
• data lines vertically offset from the stack structure and coupled to the strings of memory cells;
• a source structure offset from the stack structure and the data lines and coupled to the strings of memory cells;
• and
• complementary metal-oxide-semiconductor (CMOS) circuitry within a horizontal area of the array of the strings of memory cells and vertically offset from the stack structure, the data lines, and the source structure.

An electronic system, comprising:

• a processor device operably coupled to an input device and an output device;
• and
• a memory device operably coupled to the processor device and comprising:
• a stack structure comprising tiers each comprising:
• conductive material comprising alpha phase tungsten;
• and
• insulative material vertically neighboring the conductive material;
• a staircase structure having steps comprising edges of at least some of the tiers of the stack structure;
• tungsten pad structures on at least some of the steps of the staircase structure and individually comprising a lower concentration of the alpha phase tungsten than the conductive material of the tiers of the stack structure, at least one of the tungsten pad structures having a horizontal center offset from a horizontal center of one of the steps directly vertically thereunder;
• and
• conductive contact structures on the tungsten pad structures.