Patent ID: 11862472
Assignee: YANGTZE MEMORY TECHNOLOGIES CO., LTD.
Field: Basic materials chemistry (Chemistry)
Classification: CPC H  B  C | IPC B  C  H

Claim 0:
1. A method for forming a three-dimensional (3D) memory device, comprising:
forming a stack structure in a staircase region and a core array region, the stack structure comprising a staircase structure in the staircase region;
forming a dielectric layer over the stack structure, and a peripheral region outside the stack structure;
removing a part of the dielectric layer over the core array region to form a lateral offset of the dielectric layer between the staircase region and the core array region, such that the dielectric layer over the stack structure is higher than the dielectric layer over the core array region; and
polishing the dielectric layer using an auto-stop slurry, wherein the auto-stop slurry comprises a ceria-based abrasive.