公开(公告)号：US11251191B2

公开(公告)日：2022-02-15

申请号：US16231760

申请日：2018-12-24

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Lishan Weng ,  Fumiaki Toyama ,  Mohan Dunga

IPC: H01L27/11582 ,  H01L27/11573 ,  H01L27/11565 ,  H01L21/768 ,  H01L27/1157

Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory stack structures extending through the alternating stack, where each of the memory stack structures contains a respective memory film and a respective vertical semiconductor channel, drain regions contacting an upper end of a respective one of the vertical semiconductor channels, first contact via structures directly contacting a first subset of the drain regions and each having a first horizontal cross-sectional area, and second contact via structures directly contacting a second subset of the drain regions and each having a second horizontal cross-sectional area that is greater than the first horizontal cross-sectional area.