Sandisk Technologies Inc.

Wenguang Shi

Johann Alsmeier

Zhenyu Lu

Daxin Mao

Henry Chien

Xiaolong Hu

Koji Miyata

George Matamis

Tong Zhang

Wei Zhao

Andrew C Lin

Jixin Yu

Jiyin Xu

Yingda Dong

Raghuveer S Makala

Jian Feng Chen

Christopher John Petti

James K Kai

Peter Rabkin

Gerrit Jan Hemink

Man Lung Mui

Ching-Huang Lu

Yao-Sheng Lee

Sateesh Koka

Kensuke Yamaguchi

Hiro Kinoshita

Chun Ge

Junichi Ariyoshi

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

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

An alternating stack of insulator layers and spacer material layers is formed over a substrate. Stepped surfaces are formed in a contact region in which contact via structures are to be subsequently formed. An epitaxial semiconductor pedestal can be formed by a single epitaxial deposition process that is performed after formation of the stepped surfaces and prior to formation of memory openings, or a combination of a first epitaxial deposition process performed prior to formation of memory openings and a second epitaxial deposition process performed after formation of the memory openings. The epitaxial semiconductor pedestal can have a top surface that is located above a topmost surface of the alternating stack. The spacer material layers are formed as, or can be replaced with, electrically conductive layers. Backside contact via structures can be subsequently formed.

Three dimensional memory device with epitaxial semiconductor pedestal for peripheral transistors

Peripheral devices for a three-dimensional memory device can be formed over an array of memory stack structures to increase areal efficiency of a semiconductor chip. First contact via structures and first metal lines are formed over an array of memory stack structures and an alternating stack of insulating layers and electrically conductive layers. A semiconductor material layer including a single crystalline semiconductor material or a polycrystalline semiconductor material is formed over first metal lines. After formation of semiconductor devices on or in the semiconductor material layer, metal interconnect structures including second metal lines and additional conductive via structures are formed to electrically connect nodes of the semiconductor devices to respective first metal lines and to memory devices underneath.

Three-dimensional memory device containing CMOS devices over memory stack structures

A multi-tier memory device is formed over a substrate such that memory stack structures extend through an alternating stack of insulating layers and electrically conductive layers within each tier. Bit lines are formed between an underlying tier having drain regions over semiconductor channels and an overlying tier having drain regions under semiconductor channel, such that the bit lines are shared between the underlying tier and the overlying tier. Source lines can be formed over each tier in which source regions overlie semiconductor channels and drain regions. If another tier is present above the source lines, the source lines can be shared between two vertically neighboring tiers.

Multi tier three-dimensional memory devices including vertically shared bit lines

A method of fabricating a memory device is provided. The method includes forming a first alternating stack of insulator layers and spacer material layers over a semiconductor substrate, etching the first alternating stack to expose a single crystalline semiconductor material, forming a first epitaxial semiconductor pedestal on the single crystalline semiconductor material, such that the first epitaxial semiconductor pedestal is in epitaxial alignment with the single crystalline semiconductor material, forming an array of memory stack structures through the first alternating stack, and forming at least one semiconductor device over the first epitaxial semiconductor pedestal.

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Milpitas, CA, United States of America

Wenguang Shi