Patent ID: 11973026
Assignee: SANDISK TECHNOLOGIES, INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A method of forming a three-dimensional memory device, comprising:
forming an alternating stack of insulating layers and sacrificial material layers over a substrate;
forming memory openings through the alternating stack in a memory array region;
forming memory opening fill structures comprising a memory film and a vertical semiconductor channel in the memory openings;
forming via cavities in a contact region through a respective subset of layers within the alternating stack by performing anisotropic etch processes;
forming via cavity fill structures in the via cavities, wherein each of the via cavity fill structures comprises an insulating spacer and a sacrificial via fill material portion embedded within the insulating spacer which completely fill the via cavities;
replacing the sacrificial material layers with electrically conductive layers while the via cavities are completely filled with the via cavity fill structures;
removing the sacrificial via fill material portions selective to the insulating spacers; and
forming contact via structures vertically extending through a bottom portion of a respective one of the insulating spacers to a top surface of a respective underlying one of the electrically conductive layers.