Three-dimensional memory device containing auxiliary support pillar structures and method of making the same
AssigneeSanDisk Technologies LLC
InventorsShunsuke Takuma, Seiji Shimabukuro, Kengo Kajiwara
Life of this patent
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Abstract
A alternating stack of insulating layers and sacrificial material layers is formed over a substrate. An array of memory opening fill structures and an array of support pillar structures are formed through the alternating stack. Backside trenches are formed through the alternating stack by performing an anisotropic etch process. The anisotropic etch process etches peripheral portions of a subset of the array of support pillar structures. The sacrificial material layers are replaced with electrically conductive layer by forming backside recesses while the support pillar structures provide mechanical support to the insulating layers.
Claims20
A three-dimensional memory device, comprising:
- first and second alternating stacks of insulating layers and electrically conductive layers located over a substrate;
- a backside trench separating the first and the second alternating stacks, the backside trench laterally extends along a first horizontal direction;
- an array of memory openings vertically extending through the first and the second alternating stacks in a memory array region in which each layer of the at least one alternating stack is present;
- an array of memory opening fill structures located within the array of memory openings, wherein each of the memory opening fill structures comprises a memory film and a vertical semiconductor channel;
- an array of support pillar structures vertically extending through the first and second alternating stacks in a contact region in which the electrically conductive layers have variable lateral extents that decrease with a vertical distance from the substrate;
- and
- a backside trench fill structure located entirely in the backside trench and directly contacting sidewalls of a first subset of the support pillar structures.
A three-dimensional memory device, comprising:
- first and second alternating stacks of insulating layers and electrically conductive layers located over a substrate;
- a backside trench separating the first and the second alternating stacks, the backside trench laterally extends along a first horizontal direction;
- an array of memory openings vertically extending through the first and the second alternating stacks in a memory array region in which each layer of the at least one alternating stack is present;
- an array of memory opening fill structures located within the array of memory openings, wherein each of the memory opening fill structures comprises a memory film and a vertical semiconductor channel;
- an array of support pillar structures vertically extending through the first and second alternating stacks in a contact region in which the electrically conductive layers have variable lateral extents that decrease with a vertical distance from the substrate;
- and
- a backside trench fill structure located in the backside trench;
- wherein:
- a first subset of the support pillar structures consists essentially of a dielectric material;
- a second subset of the support pillar structures comprises a same set of materials as the memory opening fill structures;
- the first subset of the support pillar structures is located closer to the backside trench fill structure than the second subset of the support pillar structures;
- and
- the backside trench fill structure is in direct contact with a sidewall of at least one support pillar structure of the array of support pillar structures.
Dependencies are inferred from the claim text.