MICROELECTRONIC DEVICES WITH A TIERED STACK OF CONDUCTIVE, INSULATIVE, AND PARTIALLY-SACRIFICIAL STRUCTURES, AND RELATED SYSTEMS AND METHODS

Microelectronic devices include a region with a tiered stack that includes insulative, conductive, and non-conductive structures arranged in tiers. The insulative structures vertically alternate with both the conductive and the non-conductive structures. Each of the conductive structures is vertically spaced from another of the conductive structures by at least one of the non-conductive structures and at least two of the insulative structures. A composition of the non-conductive structures differs from a composition of the insulative structures. In methods of fabrication, a precursor stack is formed to include the insulative structures vertically alternating with first and second non-conductive structures. In a region of the precursor stack, the first non-conductive structures are removed, forming voids between multi-structure tier groups. Conductive structures are formed in the voids. Electronic systems are also disclosed.