公开(公告)号：US09728547B1

公开(公告)日：2017-08-08

申请号：US15159034

申请日：2016-05-19

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Shingo Ohsaki ,  Hiroshi Kariya ,  Takuro Maede ,  Takeshi Kawamura

IPC: H01L29/792 ,  H01L27/11556 ,  H01L21/02 ,  H01L21/311 ,  H01L21/768 ,  H01L27/11582 ,  H01L21/3213 ,  H01L27/11563 ,  H01L27/11578 ,  H01L27/1157 ,  H01L27/11565 ,  H01L27/11519

CPC classification number: H01L27/1157 ,  H01L21/02178 ,  H01L21/02227 ,  H01L21/0228 ,  H01L21/31144 ,  H01L21/32139 ,  H01L21/76805 ,  H01L21/76831 ,  H01L27/11563 ,  H01L27/11578 ,  H01L27/11582 ,  H01L28/00

Abstract: Unwanted erosion of dielectric materials around a backside contact trench can be avoided or minimized employing an aluminum oxide liner. An aluminum oxide liner can be formed inside an insulating material layer in a backside contact trench to prevent collateral etching of the insulating material at an upper portion of the backside contact trench during an anisotropic etch that forms an insulating spacer. Alternatively, an aluminum oxide layer can be employed as a backside blocking dielectric layer. An upper portion of the aluminum oxide layer can be converted into an aluminum compound layer including aluminum and a non-metallic element other than oxygen at an upper portion of the trench, and can be employed as a protective layer during formation of a backside contact structure.