Patent ID: 11545430

Abstract:
A method used in forming a memory array comprising strings of memory cells comprises forming a conductor tier comprising conductor material on a substrate. A lower portion of a stack is formed, with the stack ultimately comprising vertically-alternating first tiers and second tiers above the conductor tier. The stack comprises laterally-spaced memory-block regions. Material of the first tiers is of different composition from material of the second tiers. A lowest of the first tiers comprises conductive first sacrificial material. Conductive second material is directly electrically coupled to the conductive first sacrificial material. The conductive first sacrificial material and the conductive second material have different reduction potentials that are at least 0.5V away from one another. A lowest of the second tiers is insulative and below the lowest first tier. The vertically-alternating first tiers and second tiers of an upper portion of the stack are formed above the lower portion. Channel-material strings are formed that extend through the first tiers and the second tiers in the upper portion to the lowest first tier in the lower portion. Horizontally-elongated trenches are formed into the stack that are individually between immediately-laterally-adjacent of the memory-block regions and extend to the conductive first sacrificial material and the conductive second material in the lowest first tier. The conductive first sacrificial material is galvanically etched through the trenches. The lowest second tier is removed after the galvanically etching. After removing the lowest second tier, conducting material is formed in the lowest first tier that directly electrically couples together the channel material of the individual channel-material strings and the conductor material of the conductor tier. Other embodiments, including structure independent of method, are disclosed.