Memory arrays comprising strings of memory cells and methods used in forming a memory array comprising strings of memory cells

Abstract

A memory array comprising strings of memory cells comprises laterally-spaced memory blocks individually comprising a vertical stack comprising alternating insulative tiers and conductive tiers. Strings of memory cells comprise channel-material strings that extend through the insulative tiers and the conductive tiers in the memory blocks. A through-array-via (TAV) region comprises TAV constructions that extend through the insulative tiers and the conductive tiers. The TAV constructions individually comprise a radially-outer insulative lining and a conductive core radially-inward of the insulative lining. The insulative lining comprises a radially-inner insulative material and a radially-outer insulative material that are of different compositions relative one another. The radially-outer insulative material is in radially-outer recesses that are in the first tiers as compared to the second tiers. The radially-inner insulative material extends elevationally along the insulative tiers and the conductive tiers. Other embodiments, including method, are disclosed.