公开(公告)号：US20170271261A1

公开(公告)日：2017-09-21

申请号：US15183195

申请日：2016-06-15

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Masanori TSUTSUMI ,  Kota FUNAYAMA ,  Ryoichi EHARA ,  Youko FURIHATA ,  Zhenyu LU ,  Tong ZHANG ,  Tadashi NAKAMURA

IPC: H01L23/528 ,  H01L23/522 ,  H01L21/768 ,  H01L27/115

CPC classification number: H01L21/76816 ,  H01L21/76877 ,  H01L27/11565 ,  H01L27/1157 ,  H01L27/11582

Abstract: A method of forming a monolithic three-dimensional memory device includes forming a first alternating stack over a substrate, forming an insulating cap layer, forming a first memory opening through the insulating cap layer and the first alternating stack, forming a sacrificial pillar structure in the first memory opening, forming a second alternating stack, forming a second memory opening, forming an inter-stack memory opening, forming a memory film and a first semiconductor channel layer in the inter-stack memory opening, anisotropically etching a horizontal bottom portion of the memory film and the first semiconductor channel layer to expose the substrate at the bottom of the inter-stack memory opening such that damage to portions of the first semiconductor channel layer and the memory film located adjacent to the insulating cap layer is reduced or avoided, and forming a second semiconductor channel layer in contact with the exposed substrate in the inter-stack memory opening.