US 12,464,713 B2
Memory circuitry comprising strings of memory cells and method used in forming a memory array comprising strings of memory cells
Lifang Xu, Boise, ID (US); Richard J. Hill, Boise, ID (US); Yoshiaki Fukuzumi, Kanagawa (JP); and Paolo Tessariol, Arcore (IT)
Assigned to Micron Technology, Inc., Boise, ID (US)
Filed by Micron Technology, Inc., Boise, ID (US)
Filed on Feb. 4, 2022, as Appl. No. 17/665,346.
Prior Publication US 2023/0255023 A1, Aug. 10, 2023
Int. Cl. H01L 27/11556 (2017.01); H01L 21/3205 (2006.01); H01L 21/4763 (2006.01); H01L 21/70 (2006.01); H10B 12/00 (2023.01); H10B 41/10 (2023.01); H10B 41/27 (2023.01); H10B 43/10 (2023.01); H10B 43/27 (2023.01); G11C 16/04 (2006.01)
CPC H10B 41/27 (2023.02) [H01L 21/3205 (2013.01); H01L 21/4763 (2013.01); H01L 21/70 (2013.01); H10B 12/0387 (2023.02); H10B 41/10 (2023.02); H10B 43/10 (2023.02); H10B 43/27 (2023.02); G11C 16/0483 (2013.01)] 20 Claims
OG exemplary drawing
 
1. Memory circuitry comprising strings of memory cells, comprising:
memory blocks individually comprising a vertical stack comprising alternating insulative tiers and conductive tiers, channel-material strings of memory cells extending through the insulative tiers and the conductive tiers in a memory-array region, the insulative tiers and the conductive tiers of the memory blocks extending from the memory-array region into a stair-step region;
individual of the memory blocks in the stair-step region comprising a flight of operative stairs, individual of the operative stairs comprising one of the conductive tiers;
at least some immediately-laterally-adjacent of the individual memory blocks in the stair-step region having their flights of operative stairs laterally-separated by a stack comprising two vertically-alternating different-composition insulative materials; and
walls that are individually laterally between the immediately-laterally-adjacent memory blocks in the memory-array region, the walls not being laterally-adjacent said flights of operative stairs, the walls individually comprising an end portion that is in the stack comprising the two vertically-alternating different-composition insulative materials.