Sandisk Technologies Inc.

Roshan Jayakhar Tirukkonda

Raghuveer S Makala

Senaka Kanakamedala

Rahul Sharangpani

Adarsh Rajashekhar

Monica Titus

Fei Zhou

Ramy Nashed Bassely Said

Bing Zhou

A method of forming a structure includes forming an alternating stack of first material layers and second material layers over a substrate, forming a first etch mask material layer, forming a first cladding liner, and forming a via opening through the alternating stack by performing an anisotropic etch process that employs a combination of at least the first cladding liner and the first etch mask material layer as a composite etch mask structure.

Method of making a three-dimensional memory device using composite hard masks for formation of deep via openings

A method of forming a structure includes forming an alternating stack of first material layers and second material layers over a substrate, forming a mask layer over the alternating stack, forming a cavity in the mask layer, forming a first cladding liner on a sidewall of the cavity in the mask layer, and forming a via opening the alternating stack by performing an anisotropic etch process that transfers a pattern of the cavity in the mask layer through the alternating stack using a combination of the first cladding liner and the mask layer as an etch mask.

A source-level semiconductor layer and an alternating stack of first material layers and second material layers is formed above a substrate. A hard mask layer is formed over the alternating stack, and is subsequently patterned to provide a pattern of cavities therethrough. Via openings are formed through the alternating stack by performing an anisotropic etch process. A cladding liner is formed on sidewalls of the cavities in the hard mask layer and on a top surface of the hard mask layer. The via openings are vertically extended at least through the source-level semiconductor layer by performing a second anisotropic etch process employing a combination of the cladding liner and the hard mask layer as an etch mask.

A method includes forming an alternating stack of first and second layers, forming a composite hard mask layer over the alternating stack, forming openings in the hard mask, and forming via openings through the alternating stack by performing an anisotropic etch process that transfers a pattern of the openings in the composite hard mask layer through the alternating stack. The compositing hard mask includes a first cladding material layer which has higher etch resistance than upper and lower patterning films of the composite hard mask.

An alternating stack of first material layers and second material layers can be formed over a semiconductor material layer. A patterning film is formed over the alternating stack, and openings are formed through the patterning film. Via openings are formed through the alternating stack at least to a top surface of the semiconductor material layer by performing a first anisotropic etch process that transfers a pattern of the openings in the patterning film. A cladding liner can be formed on a top surface of the patterning film and sidewalls of the openings in the pattering film. The via openings can be vertically extended through the semiconductor material layer at least to a bottom surface of the semiconductor material layer by performing a second anisotropic etch process employing the cladding liner as an etch mask.

A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers and memory stack structures vertically extending through the alternating stack. Each of the memory stack structures includes a vertical semiconductor channel and a vertical stack of ferroelectric memory elements surrounding the vertical semiconductor channel and located at levels of the electrically conductive layers. Each of the ferroelectric memory elements includes a respective vertical stack of a first ferroelectric material portion and a second ferroelectric material portion that differs from the first ferroelectric material portion by at least one of a material composition and a lateral thickness.

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Milpitas, CA, United States of America

Roshan Jayakhar Tirukkonda