Abstract: A method of forming a reversible resistance-switching metal-insulator-metal (“MIM”) stack is provided, the method including forming a first conducting layer comprising a degenerately doped semiconductor material, and forming a carbon-based reversible resistance-switching material above the first conducting layer. Other aspects are also provided.
Abstract: A method of programming a nonvolatile memory device includes (i) providing a nonvolatile memory cell comprising a diode in series with at least one metal oxide, (ii) applying a first forward bias to change a resistivity state of the metal oxide from a first state to a second state; (iii) applying a second forward bias to change a resistivity state of the metal oxide from a second state to a third state; and (iv) applying a third forward bias to change a resistivity state of the metal oxide from a third state to a fourth state. The fourth resistivity state is higher than the third resistivity state, the third resistivity state is lower than the second resistivity state, and the second resistivity state is lower than the first resistivity state.
Abstract: A method of programming a nonvolatile memory array including a plurality of nonvolatile memory cells, a plurality of bit lines, and a plurality of word lines, wherein each memory cell comprises a diode, or a diode and a resistivity switching element is disclosed. The method includes both bias programming the memory cells of the device.
Abstract: A method of making a two terminal nonvolatile memory cell includes forming a first electrode, forming a charge storage medium, forming a resistive element, and forming a second electrode. The charge storage medium and the resistive element are connected in parallel between the first and the second electrodes, and a presence or absence of charge being stored in the charge storage medium affects a resistivity of the resistive element.
Abstract: An integrated circuit having a three-dimensional memory array provides for a given number of memory planes, but may be fabricated instead to include a lesser number of memory planes by omitting the masks and processing steps associated with the omitted memory planes, without changing any of the other fabrication masks for the other memory planes or for the remainder of the device, and without requiring routing or other configuration changes to the read or read/write path for the array. Control circuitry for selectively enabling certain layer selector circuits is configurable, and the layer selector circuits are suitably arranged, to couple a respective array line on an implemented memory layer to each respective I/O bus line irrespective of the number of implemented memory planes.
Abstract: Methods, apparatus, and systems in accordance with this invention include memories that include a data array and a configuration array adapted to store configuration information for configuring the data array. The data array and the configuration array include a plurality of wordlines and a plurality of bitlines. The plurality of wordlines in the data array extend in the same direction as the plurality of wordlines in the configuration array. Likewise, the plurality of bitlines in the data array extend in the same direction as the plurality of bitlines in the configuration array. The configuration array may include a wordline driver layout, a bitline driver layout, relative positions of zia contact regions, a diode sensing orientation, a sense amplifier layout, a voltage regulator layout, and a layout of conductors proximate to the array that are each substantially similar to corresponding elements of the data array. Numerous other aspects are disclosed.
Abstract: Level shift circuits are disclosed for level shifting an input signal corresponding to a first voltage domain, to generate a pair of complementary output signals corresponding to a second, higher-voltage domain. Snap-back sensitive devices in a discharge circuit for a high voltage output node are protected, irrespective of the loading on the output node, and without requiring precise transistor sizing as a function of the output loading. The snap-back sensitive devices are protected by a voltage shifter circuit in series with the sensitive devices, to limit the voltage across the sensitive devices, even for a high capacitance output node at its highest output voltage. The voltage shifter circuit is then bypassed to provide for an output low level that fully reaches the lower power supply rail.
Abstract: A multiple polarity reversible charge pump circuit is disclosed which, in certain embodiments, may be configured to generate a positive voltage at times and may be reversed to generate a negative voltage at other times. Such a charge pump circuit is advantageous if both the positive and negative voltage are not simultaneously required. In certain other embodiments, a charge pump circuit generates a high output current for only a positive boosted voltage in one mode of operation, but lower current positive and negative boosted voltage outputs in another mode of operation. Use with certain erasable memory array technologies is disclosed, particularly certain resistive passive element memory cells, and more particularly in a three-dimensional memory array.
Abstract: Level shift circuits are disclosed for level shifting an input signal corresponding to a first voltage domain, to generate a pair of complementary output signals corresponding to a second, higher-voltage domain. Snap-back sensitive devices in a discharge circuit for a high voltage output node are protected, irrespective of the loading on the output node, and without requiring precise transistor sizing as a function of the output loading. The snap-back sensitive devices are protected by a voltage shifter circuit in series with the sensitive devices, to limit the voltage across the sensitive devices, even for a high capacitance output node at its highest output voltage. The voltage shifter circuit is then bypassed to provide for an output low level that fully reaches the lower power supply rail.
Abstract: The embodiments described herein can be used to enable one-time or few-time programmable memories to work with existing consumer electronic devices (such as those that work with flash—an erasable, non-volatile memory) without requiring a firmware upgrade, thereby providing backwards compatibility while minimizing user impact. As such, these embodiments are a viable way to bridge one-time or few-time programmable memories with existing consumer electronic devices that have flash card slots. These embodiments also allow future consumer electronic devices to be designed without updating firmware to include a file system customized for a one-time or few-time programmable memory.
Type:
Grant
Filed:
April 27, 2007
Date of Patent:
March 30, 2010
Assignee:
SanDisk 3D LLC
Inventors:
Christopher S. Moore, Adrian Jeday, Matt Fruin, Chia Yang, Derek Bosch
Abstract: Methods of forming planar carbon nanotube (“CNT”) resistivity-switching materials for use in memory cells are provided, that include depositing first dielectric material, patterning the first dielectric material, etching the first dielectric material to form a feature within the first dielectric material, depositing CNT resistivity-switching material over the first dielectric material to fill the feature at least partially with the CNT resistivity-switching material, depositing second dielectric material over the CNT resistivity-switching material, and planarizing the second dielectric material and the CNT resistivity-switching material so as to expose at least a portion of the CNT resistivity-switching material within the feature. Other aspects are also provided.
Abstract: A method is described for forming a nonvolatile one-time-programmable memory cell having reduced programming voltage. A contiguous p-i-n diode is paired with a dielectric rupture antifuse formed of a high-dielectric-constant material, having a dielectric constant greater than about 8. In preferred embodiments, the high-dielectric-constant material is formed by atomic layer deposition. The diode is preferably formed of deposited low-defect semiconductor material, crystallized in contact with a silicide. A monolithic three dimensional memory array of such cells can be formed in stacked memory levels above the wafer substrate.
Abstract: A method creates pillar structures on a semiconductor wafer and includes the steps of providing a layer of semiconductor. A layer of photoresist is applied over the layer of semiconductor. The layer of photoresist is exposed with an initial pattern of light to effect the layer of photoresist. The photoresist layer is then etched away to provide a photoresist pattern to create the pillar structures. The photoresist pattern is processed in the layer of photoresist after the step of exposing the layer of photoresist and prior to the step of etching to reduce the dimensions of the photoresist pattern in the layer of photoresist.
Type:
Grant
Filed:
September 28, 2007
Date of Patent:
March 23, 2010
Assignee:
Sandisk 3D LLC
Inventors:
Yung-Tin Chen, Michael Chan, Paul Poon, Steven J. Radigan
Abstract: A method of making a nonvolatile memory device includes forming a first electrode, forming at least one nonvolatile memory cell including a diode and a metal oxide antifuse dielectric layer over the first electrode, and forming a second electrode over the at least one nonvolatile memory cell. In use, the diode acts as a read/write element of the nonvolatile memory cell by switching from a first resistivity state to a second resistivity state different from the first resistivity state in response to an applied bias.
Abstract: A chemical vapor deposition method provides a smooth continuous germanium film layer, which is deposited on a metallic substrate at a sufficiently lower temperature to provide a germanium device suitable for use with temperature sensitive materials such as aluminum and copper. Another chemical vapor deposition method provides a smooth continuous silicon germanium film layer, which is deposited on a silicon dioxide substrate at a sufficiently low temperature to provide a germanium device suitable for use with temperature sensitive materials such as aluminum, copper and chalcogenides memory materials.
Abstract: In some aspects, a method of forming a carbon nano-tube (CNT) memory cell is provided that includes (1) forming a first conductor; (2) forming a steering element above the first conductor; (3) forming a first conducting layer above the first conductor; (4) forming a CNT material above the first conducting layer; (5) implanting a selected implant species into the CNT material; (6) forming a second conducting layer above the CNT material; (7) etching the first conducting layer, CNT material and second conducting layer to form a metal-insulator-metal (MIM) stack; and (8) forming a second conductor above the CNT material and the steering element. Numerous other aspects are provided.
Abstract: A method of forming a memory cell is provided, the method including forming a first pillar-shaped element comprising a first semiconductor material, forming a first mold comprising an opening self-aligned with the first pillar-shaped element, and depositing a second semiconductor material in the opening to form a second pillar-shaped element above the first pillar-shaped element. Other aspects are also provided.
Type:
Application
Filed:
November 2, 2009
Publication date:
February 25, 2010
Applicant:
SanDisk 3D LLC
Inventors:
Kang-Jay Hsia, Calvin Li, Christopher Petti
Abstract: A method to form a rewriteable nonvolatile memory cell is disclosed, the cell comprising a steering element in series with a carbon nanotube fabric. The steering element is preferably a diode, but may also be a transistor. The carbon nanotube fabric reversibly changes resistivity when subjected to an appropriate electrical pulse. The different resistivity states of the carbon nanotube fabric can be sensed, and can correspond to distinct data states of the memory cell. A first memory level of such memory cells can be monolithically formed above a substrate, a second memory level monolithically formed above the first, and so on, forming a highly dense monolithic three dimensional memory array of stacked memory levels.
Abstract: Methods of forming memory cells are disclosed which include forming a pillar above a substrate, the pillar including a steering element and a memory element, and performing one or more etches vertically through the memory element, but not the steering element, to form multiple memory cells that share a single steering element. Memory cells formed from such methods, as well as numerous other aspects are also disclosed.
Type:
Application
Filed:
August 13, 2009
Publication date:
February 18, 2010
Applicant:
SANDISK 3D LLC
Inventors:
Huiwen Xu, Er-Xuan Ping, Roy E. Scheuerlein
Abstract: Methods of forming memory cells are disclosed which include forming a pillar above a substrate, the pillar including a steering element and a memory element, and performing one or more etches vertically through the pillar to form multiple memory cells. Memory cells formed from such methods, as well as numerous other aspects are also disclosed.