Patent ID: 11972954
Assignee: SANDISK TECHNOLOGIES, INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 19:
20. The method of claim 19, further comprising:
forming memory opening fill structures each comprising a memory film and a vertical semiconductor channel in the respective via openings;
forming a backside trench through the alternating stack, the semiconductor material layer and the source-level sacrificial layer and into an upper portion of the lower source-level semiconductor layer;
selectively etching the source-level sacrificial layer through the backside trench to form a source cavity;
etching a portion of the memory films exposed in the source cavity to expose sidewalls of the vertical semiconductor channels in the source cavity; and
forming a doped semiconductor source contact layer in the source cavity, wherein the doped semiconductor source contact layer contacts the exposed sidewalls of the vertical semiconductor channels.