Patent ID: 11950419
Assignee: YANGTZE MEMORY TECHNOLOGIES CO., LTD.
Field: nan (nan)
Classification: CPC H | IPC H

Claim 17:
18. A method for forming a three-dimensional (3D) memory device, comprising:
forming a stack structure of a plurality of first layers and a plurality of second layers interleaved above a substrate;
forming a staircase in a staircase region of the stack structure, the staircase comprising a plurality of stairs;
forming a plurality of groups of support structures in the staircase; and
forming a contact on a respective one of the stairs; and
forming a fourth support structure between adjacent groups of support structures, wherein
the plurality of groups of support structures each comprises three support structures, wherein projections of the three support structures form a triangular shape in a plane parallel to a first direction, and
in a second direction perpendicular to the first direction, a distance between the fourth support structure and one of the three support structures in one of the adjacent groups is greater than or equal to half of a critical dimension of the fourth support structure and less than or equal to the critical dimension of the fourth support structure.