Abstract: Methods for producing RRAM resistive switching elements having optimal switching behavior include crystalline phase structural changes. Structural changes indicative of optimal switching behavior include hafnium oxide phases in an interfacial region between a resistive switching layer and an electrode.

Abstract: A reversible resistance-switching metal-insulator-metal (MIM) stack is provided which can be set to a low resistance state with a first polarity signal and reset to a higher resistance state with a second polarity signal. The first polarity signal is opposite in polarity than the second polarity signal. In one approach, the MIM stack includes a carbon-based reversible resistivity switching material such as a carbon nanotube material. The MIM stack can further include one or more additional reversible resistivity switching materials such as metal oxide above and/or below the carbon-based reversible resistivity switching material. In another approach, a metal oxide layer is between separate layers of carbon-based reversible resistivity switching material.

Abstract: A system connects a signal driver to a first control line that is connected to a first non-volatile storage element, charges the first control line while the signal driver is connected to the first control line, disconnects the signal driver from the first control line while the first control line remains charged from the signal driver, connects the signal driver to a second control line that is connected to a second non-volatile storage element, charges the second control line using the signal driver while the signal driver is connected to the second control line, and disconnects the signal driver from the second control line. The disconnecting of the signal driver from the first control line, the connecting the signal driver to the second control line and the charging of the second control line are performed without waiting for the first non-volatile storage element's program operation to complete.

Abstract: A nonvolatile memory element is disclosed comprising a first electrode, a near-stoichiometric metal oxide memory layer having bistable resistance, and a second electrode in contact with the near-stoichiometric metal oxide memory layer. At least one electrode is a resistive electrode comprising a sub-stoichiometric transition metal nitride or oxynitride, and has a resistivity between 0.1 and 10 ?cm. The resistive electrode provides the functionality of an embedded current-limiting resistor and also serves as a source and sink of oxygen vacancies for setting and resetting the resistance state of the metal oxide layer. Novel fabrication methods for the second electrode are also disclosed.

Abstract: A three-dimensional array especially adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. A two-dimensional array of bit lines to which the memory elements of all planes are connected is oriented vertically from the substrate and through the plurality of planes. A single-sided word line architecture provides a word line exclusively for each row of memory elements instead of sharing one word line between two rows of memory elements thereby avoids linking the memory element across the array across the word lines. While the row of memory elements is also being accessed by a corresponding row of local bit lines, there is no extension of coupling between adjacent rows of local bit lines and therefore leakage currents beyond the word line.

Abstract: Provided are resistive random access memory (ReRAM) cells, each having three or more resistive states and being capable of storing multiple bits of data, as well as methods of fabricating and operating such ReRAM cells. Such ReRAM cells or, more specifically, their resistive switching layer have wide range of resistive states and are capable of being very conductive (e.g., about 1 kOhm) in one state and very resistive (e.g., about 1 MOhm) in another state. In some embodiments, a resistance ratio between resistive states may be between 10 and 1,000 even up to 10,000. The resistive switching layers also allow establishing stable and distinct intermediate resistive states that may be assigned different data values. These layers may be configured to switching between their resistive states using fewer programming pulses than conventional systems by using specific materials, switching pluses, and resistive state threshold.

Abstract: A three-dimensional array especially adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. A two-dimensional array of bit lines to which the memory elements of all planes are connected is oriented vertically from the substrate and through the plurality of planes. A single-sided word line architecture provides a word line exclusively for each row of memory elements instead of sharing one word line between two rows of memory elements thereby avoids linking the memory element across the array across the word lines. While the row of memory elements is also being accessed by a corresponding row of local bit lines, there is no extension of coupling between adjacent rows of local bit lines and therefore leakage currents beyond the word line.

Abstract: Provided are resistive random access memory (ReRAM) cells forming arrays and methods of operating such cells and arrays. The ReRAM cells of the same array may have the same structure, such as have the same bottom electrodes, top electrodes, and resistive switching layers. Yet, these cells may be operated in a different manner. For example, some ReRAM cells may be restively switched using lower switching voltages than other cells. The cells may also have different data retention characteristics. These differences may be achieved by using different forming operations for different cells or, more specifically, flowing forming currents in different directions for different cells. The resulting conductive paths formed within the resistive switching layers are believed to switch at or near different electrode interfaces, i.e., within a so called switching zone. In some embodiments, a switching zone of a ReRAM cell may be changed even after the initial formation.

Abstract: In a first aspect, a metal-insulator-metal (MIM) stack is provided that includes (1) a first conductive layer comprising a silicon-germanium (SiGe) alloy; (2) a resistivity-switching layer comprising a metal oxide layer formed above the first conductive layer; and (3) a second conductive layer formed above the resistivity-switching layer. A memory cell may be formed from the MIM stack. Numerous other aspects are provided.

Abstract: A method is provided for programming a memory cell having a first terminal coupled to a word line and a second terminal coupled to a bit line. During a first predetermined time interval, the word line is switched from a first standby voltage to a first voltage, the bit line is switched from a second standby voltage to a predetermined voltage, and a voltage drop across the first and second terminals is a safe voltage that does not program the memory cell. During a second predetermined time interval, the word line is switched from the first voltage to a second voltage, and a voltage drop across the first and second terminals is a programming voltage that is sufficient to program the memory cell. Numerous other aspects are provided.

Abstract: Embodiments of the invention generally include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has an improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. In one embodiment, the current limiting component comprises at least one layer of resistive material that is configured to improve the switching performance and lifetime of the formed resistive switching memory element. The electrical properties of the formed current limiting layer, or resistive layer, are configured to lower the current flow through the variable resistance layer during the logic state programming steps (i.e., “set” and “reset” steps) by adding a fixed series resistance in the formed resistive switching memory element found in the nonvolatile memory device.

Abstract: A non-volatile storage system is disclosed that includes a plurality of blocks of non-volatile storage elements, a plurality of word lines connected to the blocks of non-volatile storage elements such that each word line is connected to adjacent blocks of non-volatile storage elements, a plurality of bit lines connected to the blocks of non-volatile storage elements, multiple sets of word lines drivers such that each set of word line drivers is positioned between two adjacent blocks for driving word lines connected to the two adjacent blocks, global data lines, local data lines in selective communication with the bit lines, one or more selection circuits that selectively connect the global data lines to selected local data lines and connect unselected local data lines to one or more unselected bit line signals and control circuitry in communication with the one or more selection circuits and the global data lines.

Abstract: A die is formed with different and optimized critical dimensions in different device levels and areas of those device levels using photolithography and etch techniques. One aspect of the invention provides for a memory array formed above a substrate, with driver circuitry formed in the substrate. A level of the memory array consists of, for example, parallel rails and a fan-out region. It is desirable to maximize density of the rails and minimize cost of lithography for the entire memory array. This can be achieved by forming the rails at a tighter pitch than the CMOS circuitry beneath it, allowing cheaper lithography tools to be used when forming the CMOS, and similarly by optimizing lithography and etch techniques for a device level to produce a tight pitch in the rails, and a more relaxed pitch in the less-critical fan-out region.

Abstract: A memory cell is provided that includes a semiconductor pillar and a reversible resistance-switching element coupled to the semiconductor pillar. The semiconductor pillar includes a heavily doped bottom region of a first conductivity type, a heavily doped top region of a second conductivity type, and a lightly doped or intrinsic middle region interposed between and contacting the top and bottom regions. The middle region includes a first proportion of germanium greater than a proportion of germanium in the top region and/or the bottom region. The reversible resistivity-switching element includes a material selected from the group consisting of NiO, Nb2O5, TiO2, HfO2, Al2O3, CoO, MgOx, CrO2, VO, BN, and AlN. Numerous other aspects are provided.

Abstract: Provided are resistive random access memory (ReRAM) cells having bi-layered metal oxide structures. The layers of a bi-layered structure may have different compositions and thicknesses. Specifically, one layer may be thinner than the other layer, sometimes as much as 5 to 20 times thinner. The thinner layer may be less than 30 Angstroms thick or even less than 10 Angstroms thick. The thinner layer is generally more oxygen rich than the thicker layer. Oxygen deficiency of the thinner layer may be less than 5 atomic percent or even less than 2 atomic percent. In some embodiments, a highest oxidation state metal oxide may be used to form a thinner layer. The thinner layer typically directly interfaces with one of the electrodes, such as an electrode made from doped polysilicon. Combining these specifically configured layers into the bi-layered structure allows improving forming and operating characteristics of ReRAM cells.

Abstract: Provided are resistive random access memory (ReRAM) cells having switching layers that include hafnium, aluminum, oxygen, and nitrogen. The composition of such layers is designed to achieve desirable performance characteristics, such as low current leakage as well as low and consistent switching currents. In some embodiments, the concentration of nitrogen in a switching layer is between about 1 and 20 atomic percent or, more specifically, between about 2 and 5 atomic percent. Addition of nitrogen helps to control concentration and distribution of defects in the switching layer. Also, nitrogen as well as a combination of two metals helps with maintaining this layer in an amorphous state. Excessive amounts of nitrogen reduce defects in the layer such that switching characteristics may be completely lost. The switching layer may be deposited using various techniques, such as sputtering or atomic layer deposition (ALD).

Abstract: Provided are resistive random access memory (ReRAM) cells that include thin resistive switching layers. In some embodiments, the resistive switching layers have a thickness of less than about 50 Angstroms and even less than about 30 Angstroms. The resistive switching characteristics of such thin layers are maintained by controlling their compositions and using particular fabrication techniques. Specifically, low oxygen vacancy metal oxides, such as tantalum oxide, may be used. The concentration of oxygen vacancies may be less than 5 atomic percent. In some embodiments, the resistive switching layers also include nitrogen and. For example, compositions of some specific resistive switching layers may be represented by Ta2O5-XNY, where Y<(X?0.01). The resistive switching layers may be formed using Atomic Layer Deposition (ALD).

Abstract: A resistor array for multi-bit data storage without the need to increase the size of a memory chip or scale down the feature size of a memory cell contained within the memory chip is provided. The resistor array incorporates a number of discrete resistive elements to be selectively connected, in different series combinations, to at least one memory cell or memory device. In one configuration, by connecting each memory cell or device with at least one resistor array, a resistive switching layer found in the resistive switching memory element of the connected memory device is capable of being at multiple resistance states for storing multiple bits of digital information. During device programming operations, when a desired series combination of the resistive elements within the resistor array is selected, the resistive switching layer in the connected memory device can be in a desired resistance state.

Abstract: Provided are methods of forming nonvolatile memory elements using atomic layer deposition techniques, in which at least two different layers of a memory element are deposited sequentially and without breaking vacuum in a deposition chamber. This approach may be used to prevent oxidation of various materials used for electrodes without a need for separate oxygen barrier layers. A combination of signal lines and resistive switching layers may be used to cap the electrodes and to minimize their oxidation. As such, fewer layers are needed in a memory element. Furthermore, atomic layer deposition allows more precise control of electrode thicknesses. In some embodiments, a thickness of an electrode may be less than 50 Angstroms. Overall, atomic layer deposition of electrodes and resistive switching layers lead to smaller thicknesses of entire memory elements making them more suitable for low aspect ratio features of advanced nodes.

Abstract: A nonvolatile memory device contains a resistive switching memory element with improved device switching performance and life and methods for forming the same. The nonvolatile memory device has a first layer on a substrate, a resistive switching layer on the first layer, and a second layer. The resistive switching layer is disposed between the first layer and the second layer and the resistive switching layer comprises a material having the same morphology as the top surface of the first layer. A method of forming a nonvolatile memory element in a ReRAM device includes forming a resistive switching layer on a first layer and forming a second layer, so that the resistive switching layer is disposed between the first layer and the second layer. The resistive switching layer comprises a material formed with the same morphology as the top surface of the first layer.