Sandisk 3d LLC

Other

Sandisk Corporation

Sandisk Technologies Inc.

Aucmos Technologies Usa, Inc.

Yung-Tin Chen

Steven J Radigan

Paul Wai Kie Poon

Steven Patrick Maxwell

Kun Hou

Michael Konevecki

Christopher John Petti

Andrei Mihnea

Chun-Ming Wang

Roy E Scheuerlein

Raghuveer S Makala

Abhijit Bandyopadhyay

Huiwen Xu

Chuanbin Pan

Natalie Nguyen

Calvin K Li

Ming-Che Wu

Vance Dunton

En-Hsing Chen

Paul Poon

Luca Giovanni Fasoli

Tanmay Kumar

George Samachisa

Henry Chien

Xiying Costa

Zhida Lan

Guangle Zhou

Wei-Te Wu

Johann Alsmeier

Er-Xuan Ping

James K Kai

Peter Rabkin

Raul-Adrian Cernea

Tong Zhang

Michael L Chan

Tianhong Yan

Franz Kreupl

Wipul Jayasekara

Raul Adrian Cernea

Bing K Yen

Chi-Ming Wang

Samuel Vance Dunton

Xiying Chen

Jingyan Zhang

Li Xiao

Chu-Chen Fu

Brian Le

Timothy James Minvielle

Wipul Pemsiri Jayasekara

A 3-dimensional vertical memory string array includes high-speed ferroelectric field-effect transistor (FET) cells that are low-cost, low-power, or high-density and suitable for SCM applications. The memory circuits of the present invention provide random-access capabilities. The memory string may be formed above a planar surface of substrate and include a vertical gate electrode extending lengthwise along a vertical direction relative to the planar surface and may include (i) a ferroelectric layer over the gate electrode, (ii) a gate oxide layer; (iii) a channel layer provided over the gate oxide layer, and (iv) conductive semiconductor regions embedded in and isolated from each other by an oxide layer, wherein the gate electrode, the ferroelectric layer, the gate oxide layer, the channel layer and each adjacent pair of semiconductor regions from a storage transistor of the memory string, and wherein the adjacent pair of semiconductor regions serve as source and drain regions of the storage transistor.

Three-dimensional ferroelectric random-access memory (FeRAM)

A 3-dimensional vertical memory string array includes high-speed ferroelectric field-effect transistor (FET) cells that are low-cost, low-power, or high-density and suitable for SCM applications. The memory circuits of the present invention provide random-access capabilities. The memory string may be formed above a planar surface of substrate and include a vertical gate electrode extending lengthwise along a vertical direction relative to the planar surface and may include (i) a ferroelectric layer over the gate electrode, (ii) a gate oxide layer; (iii) a channel layer provided over the gate oxide layer; and (iv) conductive semiconductor regions embedded in and isolated from each other by an oxide layer, wherein the gate electrode, the ferroelectric layer, the gate oxide layer, the channel layer and each adjacent pair of semiconductor regions from a storage transistor of the memory string, and wherein the adjacent pair of semiconductor regions serve as source and drain regions of the storage transistor.

A ferroelectric static random access memory (FeSRAM) cell includes (a) first and second cross-coupled inverters connected between a power supply voltage signal and a ground reference voltage signal and holding a data signal represented in a complementary manner in first and second common data terminals; (b) first and second select transistors coupled respectively to the first and second common data terminals of the cross-coupled inverters; and (c) first, second, third and fourth ferroelectric capacitors, wherein the first and second ferroelectric capacitors couple the first common data terminal to the power supply voltage signal and the ground reference voltage signal, respectively, and wherein the third and the fourth ferroelectric capacitors couple the second common data terminal to the power supply voltage signal and the ground reference voltage signal, respectively.

Ferroelectric memory cell without a plate line

A multiple junction thin film transistor (TFT) is disclosed. The body of the TFT may have an n+ layer residing in a p&#x2212; region of the body. The TFT may have an n+ source and an n+ drain on either side of the p&#x2212; region of the body. Thus, the TFT has an n+/p&#x2212;/n+/p&#x2212;/n+ structure in this example. The n+ layer in the p&#x2212; region increases the breakdown voltage. Also, drive current is increased. The impurity concentration in the n+ layer in the p&#x2212; body and/or thickness of the n+ layer in the p&#x2212; body may be tuned to increase performance of the TFT. In an alternative, the body of the TFT has a p+ layer residing in an n&#x2212; region of the body. The TFT may have a p+ source and a p+ drain on either side of the p&#x2212; region of the body.

Multiple junction thin film transistor

A first patterned stack and a second patterned stack are formed over a substrate, each of which includes a bottom semiconductor layer, a bottom dielectric spacer layer, a conductive material layer, and a top dielectric spacer layer. Gate dielectrics and vertical semiconductor portions are sequentially formed on each patterned stack. Vertical semiconductor portions are removed from around the second patterned stack, while masked around the first patterned stack. Electrical dopants are introduced to top regions and bottom regions of the remaining vertical semiconductor portions to form a vertical switching device that includes the first patterned stack, while the second patterned stack functions as a horizontal interconnect structure. The vertical switching device can be a transistor or a gated diode.

Vertical transistor and local interconnect structure

Methods for forming a dual gate structure for a vertical TFT are described. The dual gate structure may be formed by performing a first etching process that includes forming a first set of trenches by etching a first set of oxide pillars to a first depth and forming a second set of trenches by etching a second set of oxide pillars to a second depth higher than the first depth, forming a first set of gate structures within the first set of trenches, forming a second set of gate structures within the second set of trenches, performing a second etching process that includes forming a third set of trenches by etching the first set of gate structures from a second initial depth to a third depth and forming a fourth set of trenches by etching the second set of gate structures to a fourth depth higher than the third depth.

Dual gate structure

In some embodiments, a memory array is provided that includes (1) a first memory cell having (a) a first conductive line; (b) a first bipolar storage element formed above the first conductive line; and (c) a second conductive line formed above the first bipolar storage element; and (2) a second memory cell formed above the first memory cell and having (a) a second bipolar storage element formed above the second conductive line; and (b) a third conductive line formed above the second bipolar storage element. The first and second memory cells share the second conductive line; the first bipolar storage element has a first storage element polarity orientation within the first memory cell; the second bipolar storage element has a second storage element polarity orientation within the second memory cell; and the second storage element polarity orientation is opposite the first storage element polarity orientation. Numerous other aspects are provided.

Multi-level memory arrays with memory cells that employ bipolar storage elements and methods of forming the same

A 3D array of nonvolatile memory has each read/write element accessed at a crossing between a word line and a bit line. The read/write element forms a tubular electrode having an outside shell of R/W material enclosing an oxide core. In a rectangular form, one side of the electrode contacts the word line and another side contacts the bit line. The thickness of the shell rather than its surface areas in contact with the word line and bit line determines the conduction cross-section and therefore the resistance. By adjusting the thickness of the shell, independent of its contact area with either the word line or bit line, each read/write element can operate with a much increased resistance and therefore much reduced current. Processes to manufacture a 3D array with such tubular R/W elements 3D array are also described.

3D non-volatile memory having low-current cells and methods

In some embodiments, a memory cell is provided that includes a metal-insulator-metal stack and a steering element coupled to the metal-insulator-metal stack. The metal-insulator-metal stack includes a first conductive layer, a reversible resistivity switching layer above the first conductive layer, and a second conductive layer above the reversible resistivity switching layer. The first conductive layer and/or the second conductive layer includes a first semiconductor material layer. The steering element includes the first semiconductor material layer. Numerous other aspects are provided.

Memory cells having storage elements that share material layers with steering elements and methods of forming the same

A memory cell is provided that includes a steering element, a metal-insulator-metal stack coupled in series with the steering element, and a conductor above the metal-insulator-metal stack. The steering element includes a diode having an n-region and a p-region. The metal-insulator-metal stack includes a reversible resistivity-switching material between a top electrode and a bottom electrode, and the top electrode includes a highly doped semiconductor material. The memory cell does not include a metal layer disposed between the metal-insulator-metal stack and the conductor. The bottom electrode includes the n-region or the p-region of the diode, and the reversible resistivity-switching material is directly adjacent the n-region or the p-region of the diode. Numerous other aspects are provided.

A three-dimensional nonvolatile memory array includes a select layer that selectively connects vertical bit lines to horizontal bit lines. Individual select switches of the select layer include two separately controllable transistors that are connected in series between a horizontal bit line and a vertical bit line. Each transistor in a select switch is connected to a different control circuit by a different select line.

High capacity select switches for three-dimensional structures

A method of forming a memory cell is provided, the method including forming a diode including a first region having a first conductivity type, counter-doping the diode to change the first region to a second conductivity type, and forming a memory element coupled in series with the diode. Other aspects are also provided.

Counter doping compensation methods to improve diode performance

A vertical NAND string device includes a semiconductor channel, where at least one end portion of the semiconductor channel extends substantially perpendicular to a major surface of a substrate, at least one semiconductor or electrically conductive landing pad embedded in the semiconductor channel, a tunnel dielectric located adjacent to the semiconductor channel, a charge storage region located adjacent to the tunnel dielectric, a blocking dielectric located adjacent to the charge storage region and a plurality of control gate electrodes extending substantially parallel to the major surface of the substrate.

Vertical NAND and method of making thereof using sequential stack etching and landing pad

A non-volatile memory cell includes a first electrode, a steering element, a metal oxide storage element located in series with the steering element, a dielectric resistor located in series with the steering element and the metal oxide storage element, and a second electrode.

Non-volatile memory cell containing an in-cell resistor

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Santa Clara, CA, United States of America

Yung-Tin Chen