Sandisk Technologies Inc.

Alliance Semiconductor Corporation

Other

Sandisk 3d LLC

National Semiconductor Corporation

Intersil Americas Inc.

Perumal Ratnam

Christopher John Petti

Tianhong Yan

Ritu Shrivastava

Roy E Scheuerlein

Masaaki Higashitani

Peter Rabkin

Tanmay Kumar

Tong Zhang

Abhijit Bandyopadhyay

Zhida Lan

Kun Hou

Alexander Kalnitsky

George Samachisa

Tz-Yi Liu

Joy T Jones

Dong Zheng

Juan Pablo Saenz

Phillip J Benzel

Guangle Zhou

Tim Chen

Chris Petti

Systems and methods for reducing leakage currents through unselected memory cells of a memory array including setting an adjustable resistance bit line structure connected to the unselected memory cells into a high resistance state or a non-conducting state during a memory operation are described. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is electrically isolated from the intrinsic polysilicon portion (e.g., via an oxide layer between the intrinsic polysilicon portion and the select gate portion). The memory cells may comprise a first conductive metal oxide (e.g., titanium oxide) that abuts a second conductive metal oxide (e.g., aluminum oxide) that abuts a layer of amorphous silicon.

Barrier modulated cell structures with intrinsic vertical bit line architecture

A matrix rail structure is formed over a substrate. The matrix rail structure includes a pair of lengthwise sidewalls that extend along a first horizontal direction and comprises, or is at least partially subsequently replaced with, a set of at least one gate electrode rail extending along the first horizontal direction and straight-sidewalled gate dielectrics. A pair of vertical semiconductor channel strips and a pair of laterally-undulating gate dielectrics can be formed on sidewalls of the matrix rail structure for each vertical field effect transistor. At least one laterally-undulating gate electrode extending along the first horizontal direction is formed on the laterally-undulating gate dielectrics. Bottom active regions and top active regions are formed at end portions of the vertical semiconductor channel strips. The vertical field effect transistors can be formed as a two-dimensional array, and may be employed as access transistors for a three-dimensional memory device.

Multi-gate vertical field effect transistor with channel strips laterally confined by gate dielectric layers, and method of making thereof

Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation are described. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.

Memory hole bit line structures

A three-dimensional memory device includes an alternating stack of electrically conductive layers and insulating layers located over a top surface of a substrate, semiconductor local bit lines extending perpendicular to the top surface of the substrate, and resistivity switching memory elements located at each overlap region between the electrically conductive layers and the semiconductor local bit lines. Each of the semiconductor local bit lines includes a plurality of drain regions located at each level of the electrically conductive layers, and having a doping of a first conductivity type, and a semiconductor channel vertically extending from a level of a bottommost electrically conductive layer within the alternating stack to a level of a topmost electrically conductive layer within the alternating stack, and contacting the plurality of drain regions within the semiconductor local bit line.

Three-dimensional memory device with vertical semiconductor bit lines located in recesses and method of making thereof

A three-dimensional resistive memory device includes an alternating stack of electrically conductive layers and insulating layers. Resistive memory elements are provided between the electrically conductive layers and a semiconductor local bit line. The semiconductor local bit line includes a heterostructure of an inner semiconductor material layer having an inner-material band gap and an outer semiconductor material layer having an outer-material band gap that is narrower than the inner-material band. A gate dielectric is located between a gate electrode and the inner semiconductor material layer.

Resistive three-dimensional memory device with heterostructure semiconductor local bit line and method of making thereof

Technology is described for reversible resistivity memory having a crystalline silicon bit line. In one aspect, a memory structure comprises a hollow pillar of crystalline silicon inside of reversible resistivity material. The crystalline silicon may serve as a bit line. The memory structure may further comprise conductive material that forms word lines coupled to the outer surface of the reversible resistivity material. A memory cell comprises a portion of the reversible resistivity material between the crystalline silicon and one of the word lines. In one aspect, the hollow pillar of crystalline silicon surrounds a gate oxide, which surrounds a conductive transistor gate. Thus, the hollow pillar of crystalline silicon may function as a channel of a transistor. In one aspect, the crystalline silicon has predominantly a (100) orientation with respect to an inner surface of the reversible resistivity material. In one aspect, the crystalline silicon is a single crystal.

Reversible resistivity memory with crystalline silicon bit line

A three-dimensional array of memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. The memory elements can be set to a low resistance state and reset to a high resistance state during standard operation by biasing appropriate voltages on the word lines and bit lines. Prior to standard operation, the memory elements undergo a forming operation, during which current through the bit lines is limited. A forming voltage is applied to the memory elements during forming with a polarity such that a higher voltage is applied to anodes and a lower voltage to cathodes.

Low forming voltage non-volatile storage device

Controlling adjustable resistance bit lines connected to word line combs

Intrinsic vertical bit line architecture

Methods for reducing leakage currents through unselected memory cells of a memory array during a memory operation. In some cases, the leakage currents through the unselected memory cells of the memory array may be reduced by setting an adjustable resistance bit line structure connected to the unselected memory cells into a non-conducting state. The adjustable resistance bit line structure may comprise a bit line structure in which the resistance of an intrinsic (or near intrinsic) polysilicon portion of the bit line structure may be adjusted via an application of a voltage to a select gate portion of the bit line structure that is not directly connected to the intrinsic polysilicon portion. The intrinsic polysilicon portion may be set into a conducting state or a non-conducting state based on the voltage applied to the select gate portion.

Setting channel voltages of adjustable resistance bit line structures using dummy word lines

Side wall bit line structures

A method of operating a memory device can include accessing at least one memory cell of a memory cell pair formed in opposing vertical sides of an opening by driving at least a first word line common to the memory cell pair to an access voltage to enable a channel conductance in both memory cells of the memory cell pair, driving a selector line, that is vertically aligned with the first word line within the opening, to a selection voltage to enable separate conductive source lines in the opposing vertical sides, and coupling one of the source lines to a source bias voltage and coupling the other of the source lines to a high impedance.

Vertical memory cells and methods of operation

A non-volatile storage device comprises: a substrate; a monolithic three dimensional array of memory cells; word lines connected to the memory cells; global bit lines; vertical bit lines connected to the memory cells; and a plurality of double gated vertically oriented select devices. The double gated vertically oriented select devices are connected to the vertical bit lines and the global bit lines so that when the double gated vertically oriented select devices are activated the vertical bit lines are in communication with the global bit lines. Each double gated vertically oriented select device has two gates that are offset from each other with respect to distance to the substrate. Both gates for the double gated vertically oriented select device need be in an 'on' condition for the double gated vertically oriented select devices to be activated.

Shared-gate vertical-TFT for vertical bit line array

A memory device may include a plurality of cell pairs each including insulator regions interposed between opposing sides of at least one common word line gate and first and second vertical sides formed by a spacing within at least one semiconductor material; and at least one selector gate vertically aligned with the word line gate within the spacing configured to enable first and second source regions in the first and second vertical sides, respectively; wherein when the selector gate is enabled, the first and second source regions are connected to different source diffusion regions.

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Fremont, CA, United States of America

Perumal Ratnam