Sandisk Technologies Inc.

Zhenyu Lu

Johann Alsmeier

Daxin Mao

Jixin Yu

Wenguang Shi

Henry Chien

Raghuveer S Makala

Hiroyuki Ogawa

Yanli Zhang

Tong Zhang

Sateesh Koka

Koji Miyata

George Matamis

Ching-Huang Lu

Yao-Sheng Lee

Wei Zhao

Kensuke Yamaguchi

Chun Ge

Xiaolong Hu

Yingda Dong

Yan Li

James K Kai

Rahul Sharangpani

Andrew C Lin

Yuki Mizutani

Kota Funayama

Somesh Peri

Hiro Kinoshita

Alexander Chu

Jiyin Xu

Makoto Yoshida

Jian Feng Chen

Christopher John Petti

Peter Rabkin

Gerrit Jan Hemink

Man Lung Mui

Jayavel Pachamuthu

Mohan Dunga

Fumiaki Toyama

Masanori Tsutsumi

Chun-Ming Wang

Ashish Kumar Baraskar

Tadashi Nakamura

Junichi Ariyoshi

Sung Tae Lee

Chenche Huang

Ryoichi Ehara

Youko Furihata

Stephen Shi

Andrey Serov

Yuichi Ikezono

Lauren Matsumoto

Contacts to peripheral devices extending through multiple tier structures of a three-dimensional memory device can be formed with minimal additional processing steps. First peripheral via cavities through a first tier structure can be formed concurrently with formation of first memory openings. Sacrificial via fill structures can be formed in the first peripheral via cavities concurrently with formation of sacrificial memory opening fill structures that are formed in the first memory openings. Second peripheral via cavities through a second tier structure can be formed concurrently with formation of word line contact via cavities that extend to top surfaces of electrically conductive layers in the first and second tier structures. After removal of the sacrificial via fill structures, the first and second peripheral via cavities can be filled with a conductive material to form peripheral contact via structures concurrently with formation of word line contact via structures.

Multi-tier memory device with through-stack peripheral contact via structures and method of making thereof

Lower level metal interconnect structures are formed over a substrate with semiconductor devices thereupon. A semiconductor material layer and an alternating stack of spacer dielectric layers and insulating layers is formed over the lower level metal interconnect structures. An array of memory stack structures is formed through the alternating stack. Trenches are formed through the alternating stack such that a staircase region is located farther away from a threshold lateral distance from the trenches, while neighboring staircase regions are formed within the threshold lateral distance from the trenches. Portions of the spacer dielectric layers proximal to the trenches are replaced with electrically conductive layers, while a remaining portion of the alternating stack is present in the staircase region. At least one through-memory-level via structure can be formed through the remaining portions of the spacer dielectric layers and the insulating layers to provide a vertically conductive path through a memory-level assembly.

Through-memory-level via structures between staircase regions in a three-dimensional memory device and method of making thereof

A semiconductor structure includes a memory-level assembly located over a substrate and including at least one alternating stack and memory stack structures vertically extending through the at least one alternating stack. Each of the at least one an alternating stack includes alternating layers of respective insulating layers and respective electrically conductive layers, and each of the electrically conductive layers in the at least one alternating stack includes a respective opening such that a periphery of a respective spacer dielectric portion located in the opening contacts a sidewall of the respective electrically conductive layers. At least one through-memory-level via structure vertically extends through each of the spacer dielectric portions and the insulating layers.

Within-array through-memory-level via structures and method of making thereof

Discrete silicon nitride portions can be formed at each level of electrically conductive layers in an alternating stack of insulating layers and the electrically conductive layers. The discrete silicon nitride portions can be employed as charge trapping material portions, each of which is laterally contacted by a tunneling dielectric portion on the front side, and by a blocking dielectric portion on the back side. The tunneling dielectric portions may be formed as discrete material portions or portions within a tunneling dielectric layer. The blocking dielectric portions may be formed as discrete material portions or portions within a blocking dielectric layer. The discrete silicon nitride portions can be formed by depositing a charge trapping material layer and selectively removing portions of the charge trapping material layer at levels of the insulating layers. Various schemes may be employed to singulate the charge trapping material layer.

Three dimensional memory device containing discrete silicon nitride charge storage regions

A linear mark extending perpendicular to a primary step direction of stepped terrace for a three-dimensional memory device can be employed as a reference feature for aligning a trimming material layer before initiating an etch-and-trim process sequence. The linear mark can be formed as a linear trench or a linear rail structure. The distance between a sidewall of each trimming material layer and the linear mark can be measured at multiple locations that are laterally spaced apart perpendicular to the primary step direction to provide statistically significant data points, which can be employed to provide an enhanced control of the staircase patterning process. Likewise, locations of patterned stepped surfaces can be measured at multiple locations to provide enhanced control of the locations of vertical steps in the stepped terrace.

Method of forming a staircase in a semiconductor device using a linear alignment control feature

A multi-tier memory device includes a first tier structure overlying a substrate and containing a first alternating stack of first insulating layers and first electrically conductive layers, and first memory stack structures each including a first memory film and a first vertical semiconductor channel, a source line overlying the first tier structure, and a second tier structure overlying the source line and containing a second alternating stack of second insulating layers and second electrically conductive layers, and second memory stack structures each including a second memory film and a second vertical semiconductor channel.

Multi-tier three-dimensional memory devices including vertically shared source lines 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 three-dimensional memory device, includes forming a lower stack structure of insulating and first sacrificial material layers over a substrate, forming first memory openings through the lower stack structure and filling the first memory openings with a sacrificial fill material, replacing the first sacrificial material layers with first electrically conductive layers, forming an upper stack structure of insulating and second sacrificial material layers over the lower stack structure after replacing the first sacrificial material layers, forming second memory openings through the upper stack structure in areas overlying the first memory openings, replacing the second sacrificial material layers with second electrically conductive layers, removing the sacrificial fill material from the first memory openings underneath the second memory openings to form inter-stack memory openings after replacing the second sacrificial material layers, and forming memory stack structures within the inter-stack memory openings.

Method of making a multilevel memory stack structure using a cavity containing a sacrificial fill material

An alternating stack of insulating layers and sacrificial material layers can be formed over a substrate. Memory stack structures and a backside trench are formed through the alternating stack. Backside recesses are formed by removing the sacrificial material layers from the backside trench selective to the insulating layers. A cobalt-semiconductor alloy portion is formed in each backside recess by reacting cobalt and a semiconductor material. Conductive material in the backside trench can be removed by an etch to electrically isolate cobalt-containing alloy portions located in different backside recesses. Electrically conductive layers including a respective cobalt-semiconductor alloy portion can be employed as word lines of a three-dimensional memory device.

Memory device containing cobalt silicide control gate electrodes and method of making thereof

Disclosed herein are methods of fabricating a source side select (SGS) transistor in 3D memory. The threshold voltage of the SGS transistor accurately meets a target threshold voltage. The SGS transistor has a semiconductor body that resides in a memory hole formed in a stack of alternating layers of two materials. During fabrication, a sacrificial layer may be removed to create recesses between dielectric layers in a stack. The sacrificial layer may be removed by introducing an etchant into slits formed in the stack. Thus, the recess may expose sidewalls of the body of the SGS transistor. An impurity may be introduced into this recess, by way of a slit, in order to dope the source side select transistor. This allows for precise control over the doping profile, which in turn provides for precise control over the threshold voltage of the SGS transistor.

Method of fabricating 3D NAND

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 memory opening can be formed through a multiple tier structure. Each tier structure includes an alternating stack of sacrificial material layers and insulating layers. After formation of a dielectric oxide layer, the memory opening is filled with a sacrificial memory opening fill structure. The sacrificial material layers are removed selective to the insulating layers and the dielectric oxide layer to form backside recesses. Physically exposed portions of the dielectric oxide layer are removed. A backside blocking dielectric and electrically conductive layers are formed in the backside recesses. Subsequently, the sacrificial memory opening fill structure is replaced with a memory stack structure including a plurality of charge storage regions and a semiconductor channel. Hydrogen or deuterium from a dielectric core may then be outdiffused into the semiconductor channel.

Multi-tier replacement memory stack structure integration scheme

Techniques for forming 3D memory arrays are disclosed. Memory openings are filled with a sacrificial material, such as silicon or nitride. Afterwards, a replacement technique is used to remove nitride from an ONON stack and replace it with a conductive material such as tungsten. Afterwards, memory cell films are formed in the memory openings. The conductive material serves as control gates of the memory cells. The control gate will not suffer from corner rounding. ONON shrinkage is avoided, which will prevent control gate shrinkage. Block oxide between the charge storage region and control gate may be deposited after control gate replacement, so the uniformity is good. Block oxide may be deposited after control gate replacement, so TiN adjacent to control gates can be thicker to prevent fluorine attacking the insulator between adjacent control gates. Therefore, control gate to control gate shorting is prevented.

Forming 3D memory cells after word line replacement

A monolithic three-dimensional memory device includes a first memory block containing a plurality of memory sub-blocks located on a substrate. Each memory sub-block includes a set of memory stack structures and a portion of alternating layers laterally surrounding the set of memory stack structures. The alternating layers include insulating layers and electrically conductive layers. A first portion of a neighboring pair of memory sub-blocks is laterally spaced from each other along a first horizontal direction by a backside contact via structure. A subset of the alternating layers contiguously extends between a second portion of the neighboring pair of memory sub-blocks through a gap in a bridge region between two portions of the backside contact via structure that are laterally spaced apart along a second horizontal direction to provide a connecting portion between the neighboring pair of memory sub-blocks.

Three-dimensional memory devices containing memory block bridges

A method of manufacturing a structure includes forming an in-process alternating stack including insulating layers and spacer material layers over a substrate, forming two sets of stepped surfaces by dividing the in-process alternating stack into a first alternating stack and a second alternating stack, the first alternating stack having first stepped surfaces and the second alternating stack having second stepped surfaces, forming at least one memory stack structure through the first alternating stack, each of the at least one memory stack structure including charge storage regions, a tunneling dielectric, and a semiconductor channel, replacing portions of the insulating layers in the first alternating stack with electrically conductive layers while leaving intact portions of the insulating layers in the second alternating stack, and forming a contact via structure through the second alternating stack to contact a peripheral semiconductor device under the second stack.

Three dimensional memory device with peripheral devices under dummy dielectric layer stack and method of making thereof

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Milpitas, CA, United States of America

Zhenyu Lu