Sandisk Technologies Inc.

Hisaya Sakai

Masanori Tsutsumi

Yoshitaka Otsu

Kota Funayama

Jo Sato

Kazuto Ohsawa

A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, memory stack structures vertically extending through the alternating stack, a finned dielectric moat structure including a dielectric core portion vertically extending through each layer within the alternating stack and a vertical stack of dielectric fin portions laterally extending outward from the dielectric core portion, a vertical stack of insulating plates and dielectric material plates laterally surrounded by the finned dielectric moat structure, and an interconnection via structure vertically extending through the vertical stack and contacting a top surface of an underlying metal interconnect structure.

Three-dimensional memory device with via structures surrounded by perforated dielectric moat structure and methods of making the same

An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory stack structures extending through the alternating stack are formed. A backside trench is formed through the alternating stack. The sacrificial material layers are replaced with electrically conductive layers. An insulating spacer and the backside contact via structure are formed within the backside trench. A dielectric isolation trench is formed by removing a peripheral portion of an upper region of the backside contact via structure and an upper portion of the insulating spacer. A dielectric isolation spacer is formed in the dielectric isolation trench to prevent an electrical short between an upper portion of the backside contact via structure and the electrically conductive layers.

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Yokkaichi, Japan

Hisaya Sakai