Patent ID: 11862558
Assignee: YANGTZE MEMORY TECHNOLOGIES CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 12:
13. The method of claim 12, wherein the performing the first patterning process comprises:
performing the first patterning process repetitively on the sacrificial word line layers and the insulating layers in the first staircase region to form stairs having treads with the first edge profile in the first section and extending in a fourth step-down direction (X direction), and stairs having treads with the first edge profile in the second section and extending in the first step-down direction (−X direction), the fourth step-down direction being opposite to the first step-down direction; and
performing the first patterning process repetitively on the sacrificial word line layers and the insulating layers in the first staircase region to form stairs having treads with a second edge profile in the first section and extending in the fourth step-down direction, and stairs having treads with the second edge profile in the second section and extending in the first step-down direction (−X direction), the first edge profile and the second edge profile being symmetric.