Sandisk Technologies Inc.

Shingo Ohsaki

Takeshi Kawamura

Takuro Maede

Hiroshi Kariya

A three-dimensional memory device includes an alternating stack of insulating layers and word lines located over a front side surface of a semiconductor substrate, memory stack structures extending through the alternating stack, in which each of the memory stack structures includes a memory film and a vertical semiconductor channel contacting an inner sidewall of the memory film, drain regions contacting a respective vertical semiconductor channel, bit lines electrically connected to the respective drain regions, driver circuitry for the memory stack structures located on a backside of the semiconductor substrate, and electrically conductive paths vertically extending through the semiconductor substrate and electrically connecting nodes of the driver circuitry to respective word lines or bit lines.

Three-dimensional memory device with driver circuitry on the backside of a substrate and method of making thereof

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.

Three-dimensional memory device with aluminum-containing etch stop layer for backside contact structure and method of making thereof

A method of fabricating a memory device includes forming a mask over a top surface of a stack of alternating insulating material layers and control gate electrodes located over a substrate, wherein the stack has a memory opening extending vertically through the stack, a semiconductor channel extends vertically in the memory opening, and a memory film is located in the memory opening between the semiconductor channel and the plurality of control gate electrodes, and the mask covers a first portion of an upper insulating layer of the stack and exposes a second portion of the upper insulating layer adjacent to the memory opening, etching the upper insulating layer through the mask to provide a recess in the second portion of the upper insulating layer, and forming a conductive material within the recess to provide a select gate electrode adjacent to the semiconductor channel in the memory opening.

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Yokkaichi, Japan

Shingo Ohsaki