The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 13, 2022
Filed:
Sep. 30, 2020
Sandisk Technologies Llc, Addison, TX (US);
SANDISK TECHNOLOGIES LLC, Addison, TX (US);
Abstract
A lower source-level dielectric etch-stop layer, a source-level sacrificial layer, and an upper source-level dielectric etch-stop layer are formed over a substrate. An alternating stack of insulating layers and sacrificial material layers is formed thereabove. Memory stack structures are formed through the alternating stack. Backside openings are formed through the alternating stack and into the in-process source-level material layers such that tapered surfaces are formed through the upper source-level dielectric etch-stop layer. A source cavity is formed by removing the source-level sacrificial layer, and a continuous source contact layer is formed in the source cavity and in peripheral portions of the backside openings. Portions of the continuous source contact layer overlying the tapered surfaces are removed by performing an isotropic etch process. Remaining portions of the continuous source contact layer comprise a source contact layer. The sacrificial material layers are replaced with electrically conductive layers.