Abstract: A method used in forming a memory array comprises forming a substrate comprising a conductive tier, a first insulator tier above the conductive tier, a sacrificial material tier above the first insulator tier, and a second insulator tier above the sacrificial material tier. A stack comprising vertically-alternating insulative tiers and wordline tiers is formed above the second insulator tier. Channel material is formed through the insulative tiers and the wordline tier. Horizontally-elongated trenches are formed through the stack to the sacrificial material tier. Sacrificial material is etched through the horizontally-elongated trenches selectively relative to material of the first insulator tier and selectively relative to material of the second insulator tier. A laterally-outer sidewall of the channel material is exposed in the sacrificial material tier. A conductive structure is formed directly against the laterally-outer sidewall of the channel material in the sacrificial material tier.