US 12,232,317 B2
Memory arrays comprising strings of memory cells and methods used in forming a memory array comprising strings of memory cells
John D. Hopkins, Meridian, ID (US); Damir Fazil, Boise, ID (US); and Michael E. Koltonski, Boise, ID (US)
Assigned to Micron Technology, Inc., Boise, ID (US)
Filed by Micron Technology, Inc., Boise, ID (US)
Filed on Feb. 8, 2022, as Appl. No. 17/666,844.
Prior Publication US 2023/0253465 A1, Aug. 10, 2023
Int. Cl. H10B 43/27 (2023.01); H01L 21/28 (2006.01); H10B 41/27 (2023.01); H10B 41/41 (2023.01); H10B 43/10 (2023.01)
CPC H10B 43/27 (2023.02) [H01L 29/40117 (2019.08); H10B 41/27 (2023.02); H10B 41/41 (2023.02); H10B 43/10 (2023.02)] 26 Claims
OG exemplary drawing
 
1. A method used in forming a memory array comprising strings of memory cells, comprising:
forming a conductor tier comprising conductor material on a substrate, the conductor tier comprising etch-stop material spanning laterally-across and laterally-between multiple locations where individual channel-material-string constructions will be formed, the etch-stop material being of different composition from an upper portion of the conductor material;
forming laterally-spaced memory-block regions individually comprising a vertical stack comprising alternating first tiers and second tiers directly above the conductor tier and the etch-stop material, material of the first tiers being of different composition from material of the second tiers;
the etch-stop material being formed to comprise (a) or (b), where
(a): laterally-opposing sides that taper laterally-inward moving deeper into the conductor tier; and
(b): laterally-opposing sides that are everywhere spaced laterally-inward of laterally-opposing sides of the laterally-spaced memory-block regions;
etching channel openings through the first tiers and the second tiers to stop on the etch-stop material; and
forming a channel-material-string construction in individual of the channel openings directly above the etch-stop material, the channel material of the channel-material-string construction directly electrically coupling to the conductor material in the conductor tier.