Sandisk Technologies Inc.

Toshiba Memory Corporation

Kota Funayama

Hiroyuki Ogawa

Takeshi Kawamura

Tong Zhang

Masatoshi Nishikawa

Toru Miwa

Masanori Tsutsumi

Zhenyu Lu

Koichi Matsuno

Naohiro Hosoda

Tadashi Nakamura

Masaaki Higashitani

Johann Alsmeier

Fumiaki Toyama

Tatsuya Hinoue

Chun-Ming Wang

Satoshi Shimizu

Jixin Yu

Yuki Mizutani

Masaki Tsuji

Fumitaka Amano

Daxin Mao

Yoshitaka Otsu

Tomohiro Kubo

Takaya Yamanaka

Dai Iwata

Yoko Furihata

Koji Miyata

Chenche Huang

Jo Sato

Youko Furihata

Makoto Yoshida

Kazuto Ohsawa

Ryoichi Ehara

Akira Matsumura

Masahiro Yaegashi

Hisaya Sakai

Masayuki Fukai

Akihiro Ueda

Lauren Matsumoto

Contact via openings are formed through a retro-stepped dielectric material portion in a three-dimensional memory device to underlying etch stop structures. The etch stop structures may include a stepped conductive or semiconductor etch stop plate overlying stepped surfaces in the staircase region. The contact via openings are extended through the etch stop structures. Alternatively, electrically conductive layers, including a topmost dummy electrically conductive layer in the staircase region, may be employed as etch stop structures. In this case, the contact via openings can be extended through the electrically conductive layers. Insulating spacers are formed at peripheral regions of the extended contact via openings. Contact via structures surrounded by the insulating spacers are formed in the extended contact via openings to a respective underlying electrically conductive layer.

Three-dimensional memory device containing etch-stop structures and self-aligned insulating spacers and method of making the same

A memory device includes a lower source-level semiconductor layer, a source contact layer, an upper source-level semiconductor layer, and an alternating stack of insulating layers and electrically conductive layers, and a memory opening fill structure vertically extending through the alternating stack and down to an upper portion of the lower source-level semiconductor layer. The memory opening fill structure includes a vertical semiconductor channel, a memory film laterally surrounding the vertical semiconductor channel, and an annular semiconductor cap contacting a bottom surface of the memory film and contacting a top surface segment of the source contact layer. The annular semiconductor cap may be employed as an etch stop structure during a manufacturing process.

Three-dimensional memory device with self-aligned etch stop rings for a source contact layer and method of making the same

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

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.

Spacerless source contact layer replacement process and three-dimensional memory device formed by the process

A memory die includes an alternating stack of insulating layers and electrically conductive layers located between a drain-side dielectric layer and a source-side dielectric layer. Memory openings vertically extend through the alternating stack. Each of the memory openings has a greater lateral dimension an interface with the source-side dielectric layer than at an interface with the drain-side dielectric layer. Memory opening fill structures are located in the memory openings. Each of the memory opening fill structures includes a vertical semiconductor channel, a vertical stack of memory elements, and a drain region. A logic die may be bonded to a source-side dielectric layer side of the memory die.

Memory die with source side of three-dimensional memory array bonded to logic die and methods of making the same

A first memory film and a sacrificial fill structure are formed within each first-tier memory opening through a first alternating stack of first insulating layers and first spacer material layers. A second alternating stack of second insulating layers and second spacer material layers is formed over the first alternating stack, and a second-tier memory opening is formed over each sacrificial fill structure. A second memory film is formed in each upper opening, and the sacrificial fill structures are removed from underneath the second-tier memory openings to form memory openings. A semiconductor channel is formed on each vertically neighboring pair of a first memory film and a second memory film as a continuous layer. The first memory film is protected by the sacrificial fill structure during formation of the second-tier memory openings.

Three-dimensional memory device with reduced etch damage to memory films and methods of making the same

A first alternating stack of first insulating layers and first spacer layers, an inter-tier dielectric layer, a sacrificial memory opening fill structure, and a second alternating stack of second insulating layers and second spacer layers are formed over a substrate. The spacer layers are formed as, or are subsequently replaced with, electrically conductive layers. A concave downward-facing surface of the inter-tier dielectric layer is formed on a convex upper surface of the sacrificial memory opening fill structure. An inter-tier memory opening is provided by forming second-tier memory opening and removing the sacrificial memory opening fill structure. A memory stack structure including a memory film is formed in the inter-tier memory opening. The memory film includes a rounded top surface at the joint between tiers to enhance its reliability.

Multi-tier memory device with rounded top part of joint structure and methods of making the same

A first tier structure is provided by forming first memory openings through a first alternating stack of first insulating layers and first spacer layers, and by forming sacrificial memory opening fill structures in the first memory openings. A second tier structure is formed over the first tier structure by forming a second alternating stack of second insulating layers and second spacer layers. Second memory openings are formed through the second tier structure in areas of the sacrificial memory opening fill structures. Distortion of the first tier structure and misalignment between the first and second memory openings is reduced or prevented by conducting thermal cycles at a lower temperature for the second tier structure than for the first tier structure.

Distortion reduction of memory openings in a multi-tier memory device through thermal cycle control

A first tier structure including a first alternating stack of first insulating layers and first sacrificial material layers is formed over a substrate. First support openings and first memory openings are formed through the first tier structure. A dielectric material portion providing electrical isolation from the substrate is formed in each first memory openings. A second tier structure including a second alternating stack of second insulating layers and second sacrificial material layers is formed the first tier structure. Second support openings and second memory openings are formed through the second tier structure above the first support openings and the first memory openings. Memory stack structures are formed in inter-tier openings formed by adjoining the first and second memory openings. The dielectric material portions provide electrical isolation between the substrate and the vertical semiconductor layers formed within support pillar structures to prevent or reduce electrical shorts to the substrate through the support pillar structures.

Three-dimensional memory device with electrically isolated support pillar structures and method of making thereof

A vertical, columnar resistor in a semiconductor device is provided, along with techniques for fabricating such a resistor. The resistor may be provided in a peripheral area of a 3D memory device which has a two-tier or other multi-tier stack of memory cells. The structure and fabrication of the resistor can be integrated with the structure and fabrication of the stack of memory cells. The resistor may comprise doped polysilicon. In an example implementation, a polysilicon pillar extends a height of a first tier of the stack and a metal pillar above the polysilicon pillar extends a height of a second tier of the stack.

Vertical resistor in 3D memory device with two-tier stack

An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory stack structures including a memory film and a vertical semiconductor channel are formed through the alternating stack in an array configuration. Backside trenches extending along a lengthwise direction are formed through the alternating stack. Backside recesses are formed by removing the sacrificial material layers. Filling of the backside recesses with electrically conductive layers can be performed without voids or with minimal voids by arranging the memory stack structures with a non-uniform pitch. The non-uniform pitch may be along the direction perpendicular to the lengthwise direction such that the nearest neighbor distance among the memory stack structures is at a minimum between the backside trenches. Alternatively or additionally, the pitch may be modulated along the lengthwise direction to provide wider spacing regions that extend perpendicular to the lengthwise direction.

Three-dimensional memory device having non-uniform spacing among memory stack structures and method of making thereof

A method of dividing drain select gate electrodes in a three-dimensional vertical memory device is provided. An alternating stack of insulating layers and spacer material layers is formed over a substrate. A first insulating cap layer is formed over the alternating stack. A plurality of memory stack structures is formed through the alternating stack and the first insulating cap layer. The first insulating cap layer is vertically recessed, and a conformal material layer is formed over protruding portions of the memory stack structures. Spacer portions are formed by an anisotropic etch of the conformal material layer such that the sidewalls of the spacer portions having protruding portions. A self-aligned separator trench with non-uniform sidewalls having protruding portions is formed through an upper portion of the alternating stack by etching the upper portions of the alternating stack between the spacer portions.

Self-aligned isolation dielectric structures for a three-dimensional memory device

A method of forming a monolithic three-dimensional memory device includes forming a first alternating stack over a substrate, forming an insulating cap layer, forming a first memory opening through the insulating cap layer and the first alternating stack, forming a sacrificial pillar structure in the first memory opening, forming a second alternating stack, forming a second memory opening, forming an inter-stack memory opening, forming a memory film and a first semiconductor channel layer in the inter-stack memory opening, anisotropically etching a horizontal bottom portion of the memory film and the first semiconductor channel layer to expose the substrate at the bottom of the inter-stack memory opening such that damage to portions of the first semiconductor channel layer and the memory film located adjacent to the insulating cap layer is reduced or avoided, and forming a second semiconductor channel layer in contact with the exposed substrate in the inter-stack memory opening.

Three-dimensional memory device containing annular etch-stop spacer and method of making thereof

A first tier structure including a first alternating stack of first insulating layers and first sacrificial material layers is formed over a substrate. First support pillar structures are formed through the first tier structure. A second tier structure including a second alternating stack of second insulating layers and second sacrificial material layers is formed over the first tier structure. Memory stack structures and second support pillar structures are formed through the second tier structure. The first and second sacrificial material layers are replaced with first and second electrically conductive layers while the first support pillar structures, the second support pillar structures, and the memory stack structures provide structural support to the first and second insulating layers. By limiting the spatial extent of the first support pillar structures within the first tier structure, electrical short to backside contact via structures can be reduced.

Multi-tier memory stack structure containing two types of support pillar structures

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Yokkaichi, Japan

Kota Funayama