US 12,457,742 B2
Three-dimensional memory device including trench bridges and methods of forming the same
Koichi Matsuno, Fremont, CA (US)
Assigned to Sandisk Technologies, Inc., Milpitas, CA (US)
Filed by SANDISK TECHNOLOGIES LLC, Addison, TX (US)
Filed on Aug. 11, 2022, as Appl. No. 17/819,081.
Prior Publication US 2024/0057331 A1, Feb. 15, 2024
Int. Cl. H10B 43/27 (2023.01); H01L 23/522 (2006.01); H10B 41/10 (2023.01); H10B 41/27 (2023.01); H10B 41/35 (2023.01); H10B 43/10 (2023.01); H10B 43/35 (2023.01)
CPC H10B 43/27 (2023.02) [H01L 23/5226 (2013.01); H10B 41/10 (2023.02); H10B 41/27 (2023.02); H10B 41/35 (2023.02); H10B 43/10 (2023.02); H10B 43/35 (2023.02)] 11 Claims
OG exemplary drawing
 
1. A three-dimensional memory device, comprising:
a pair of layer stacks laterally extending along a first horizontal direction and laterally spaced from each other along a second horizontal direction by a backside trench, wherein each of the layer stacks comprises a first-tier alternating stack of first insulating layers and first electrically conductive layers, a first insulating cap layer located over the first-tier alternating stack, and a second-tier alternating stack of second insulating layers and second electrically conductive layers located over the first insulating cap layer;
memory openings vertically extending through the pair of layer stacks;
memory opening fill structures located in the respective memory openings and comprising a respective vertical stack of memory elements and a respective vertical semiconductor channel;
a bridge structure spanning an entire width of the backside trench along the second horizontal direction, wherein a top surface of the bridge structure is located in a first horizontal plane disposed below top surfaces of the second-tier alternating stacks, and a bottom surface of the bridge structure is located in a second horizontal plane disposed above bottom surfaces of the first-tier alternating stacks; and
a backside trench fill structure located in the backside trench,
wherein:
a combination of the backside trench fill structure and the first insulating cap layers embeds the bridge structure; and
the bridge structure comprises a pair of first sidewalls that contact the first insulating cap layers within the pair of layer stacks, and comprises a top surface located within a horizontal plane including top surfaces of the first insulating cap layers.