公开(公告)号：US10192877B2

公开(公告)日：2019-01-29

申请号：US15451773

申请日：2017-03-07

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Naoto Norizuki ,  Yasuchika Okizumi ,  Shogo Mada ,  Hiroyuki Ogawa

IPC: H01L27/11551 ,  H01L27/11548 ,  H01L27/11556 ,  H01L27/11575 ,  H01L27/11582 ,  H01L27/11519 ,  H01L27/11565 ,  H01L21/311

Abstract: A mesa structure is formed over a substrate. An alternating stack of insulating layers and spacer material layers having a total height of approximately double the height of the mesa structure is formed over the substrate and the mesa structure. The spacer material layers are formed as, or are replaced with, electrically conductive layers. Portions of the alternating stack are removed from above the mesa structure by a planarization process. Stepped surfaces can be concurrently formed in a first terrace region overlying the mesa structure and in a second terrace region located at an opposite side of a memory array region of the alternating stack. A pair of level shifted stepped surfaces is formed. Contacts to the alternating stack can reach down only to the lowest surface of the pair of level shifted stepped surfaces, and can be shorter than the alternating stack.

公开(公告)号：US09905573B1

公开(公告)日：2018-02-27

申请号：US15251374

申请日：2016-08-30

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Shogo Mada ,  Akira Takahashi ,  Motoki Umeyama

IPC: H01L27/115 ,  H01L27/11582 ,  H01L27/1157 ,  H01L27/11573 ,  H01L23/535

CPC classification number: H01L27/11582 ,  H01L23/535 ,  H01L27/1157 ,  H01L27/11573

Abstract: A mesa structure is formed over peripheral devices on a substrate. An alternating stack of insulating layers and spacer material layers is formed over the substrate and the mesa structure. A region of the alternating stack overlying the mesa structure is removed to provide a region in which the layers in the alternating stack extend along a non-horizontal direction that is parallel to the dielectric sidewall of the mesa structure. Memory stack structures and backside contact via structures are formed through another region of the alternating stack that includes horizontally-extending portions of the layers within the alternating stack. The spacer material layers are provided as, or are replaced with, electrically conductive layers. Top surfaces of portions of the electrically conductive layers that extend parallel to the dielectric sidewall of the mesa structure can be contacted by word line contact via structures.