US 12,356,619 B2
Memory arrays comprising strings of memory cells and methods used in forming a memory array comprising strings of memory cells
Collin Howder, Boise, ID (US); and John D. Hopkins, Meridian, ID (US)
Assigned to Micron Technology, Inc., Boise, ID (US)
Filed by Micron Technology, Inc., Boise, ID (US)
Filed on Apr. 5, 2022, as Appl. No. 17/713,955.
Prior Publication US 2023/0320092 A1, Oct. 5, 2023
Int. Cl. H01L 27/11582 (2017.01); H10B 41/27 (2023.01); H10B 43/27 (2023.01)
CPC H10B 43/27 (2023.02) [H10B 41/27 (2023.02)] 17 Claims
OG exemplary drawing
 
1. A method used in forming a memory array comprising strings of memory cells, comprising:
forming laterally-spaced memory-block regions individually comprising a vertical stack comprising alternating first tiers and second tiers directly above conductor material of a conductor tier;
forming channel-material-string constructions that extend through the first and second tiers to a lowest of the first tiers, the channel-material-string constructions individually comprising a charge-blocking-material string, a storage-material string laterally-inward of the charge-blocking-material string, a charge-passage-material string laterally-inward of the storage-material string, and a channel-material string laterally-inward of the charge-passage-material string;
etching the storage-material string upwardly from and through the lowest first tier selectively relative to the charge-blocking-material string and selectively relative to the charge-passage-material string;
after etching the storage-material string, etching the charge-passage-material string upwardly from and through the lowest first tier selectively relative to the charge-blocking-material string and selectively relative to the channel-material string; and
forming conductive material in the lowest first tier that directly electrically couples together the channel material of individual of the channel-material strings and the conductor material of the conductor tier, the conductive material having a first vertical sidewall in direct physical contact with the channel-material string and having a second vertical sidewall opposing the first vertical sidewall and extending along multiple of the alternating first tiers and second tiers, an entirety of the second vertical sidewall being in direct physical contact with the charge-blocking-material string in a finished construction.