Method of making a three dimensional NAND device

US9305849B1 · kind B1 · utility

Assignee

• Sandisk Technologies, Inc. · US

Inventors

• Masanori Tsutsumi · Yokkaichi, JP
• Shigehiro Fujino · Yokkaichi, JP
• Sateesh Koka · Milpitas, US
• Senaka Kanakamedala · San Jose, US
• Yanli Zhang · San Jose, US
• Raghuveer S. Makala · Campbell, US
• Rahul Sharangpani · Fremont, US
• George Matamis · Danville, US
• Wei Zhao · Milpitas, US

Key dates

• Filing date: Nov 12, 2014
• Grant date: Apr 5, 2016
• Expiry date: Nov 12, 2034

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B43/50

Abstract

A monolithic three dimensional NAND string includes a semiconductor channel, an end part of the semiconductor channel extending substantially perpendicular to a major surface of a substrate, a plurality of control gate electrodes extending substantially parallel to the major surface of the substrate, a charge storage material layer located between the plurality of control gate electrodes and the semiconductor channel, a tunnel dielectric located between the charge storage material layer and the semiconductor channel, and a blocking dielectric containing a plurality of clam-shaped portions each having two horizontal portions connected by a vertical portion. Each of the plurality of control gate electrodes are located at least partially in an opening in the clam-shaped blocking dielectric, and a plurality of discrete cover oxide segments embedded in part of a thickness of the charge storage material layer and located between the blocking dielectric and the charge storage material layer.