Methods used in forming a memory array comprising strings of memory cells including insulator walls in a through-array-via region

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 above a conductor tier. The conductor tier is directly above a lower tier that comprises conductive lines that are horizontally elongated. An insulator tier is vertically between the conductor tier and the lower tier. Strings of memory cells comprise channel-material strings that extend through the insulative tiers and the conductive tiers. The channel-material strings directly electrically couple to the conductor material of the conductor tier. A through-array-via (TAV) region comprises TAVs that individually directly electrically couple to one of the conductive lines. Insulator walls are in the TAV region. The insulator walls extend vertically through the conductor tier and the insulator tier to the lower tier and are horizontally elongated. Methods are also disclosed.