Patent ID: 11903203
Assignee: MACRONIX INTERNATIONAL CO., LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 14:
15. The fabrication method of the 3D AND flash memory device according to claim 13, wherein a method of forming the channel pillar and the protective cap comprises:
forming a channel material layer on the stack structure and in the opening;
forming a spacer material layer on the channel material layer;
performing a first etch-back process to partially remove the channel material layer and the spacer material layer to form the channel pillar and a spacer and form a groove between the stack structure and the spacer;
forming a protective material layer on the stack structure, in the groove, and in the opening;
performing a second etch-back process to partially remove the protective material layer and form the protective cap in the groove, wherein the protective cap covers the channel pillar;
and removing the spacer.