Abstract: A conductive memory stack is provided. The memory stack includes a bottom electrode, a top electrode and a multi-resistive state element. The multi-resistive state element is sandwiched between the electrodes such that the top face of the bottom electrode is in contact with the multi-resistive state element's bottom face and the bottom face of the top electrode is in contact with the multi-resistive state element's top face. The bottom electrode, the top electrode and the multi-resistive state element all have sides that are adjacent to their faces. Furthermore, the sides are at least partially covered by a sidewall layer.

Abstract: A re-writable memory that uses resistive memory cell elements with non-linear IV characteristics is disclosed. Non-linearity is important in certain memory arrays to prevent unselected cells from being disturbed and to reduce the required current. Non-linearity refers to the ability of the element to block the majority of current up to a certain level, but then, once that level is reached, the element allows the majority of the current over and above that level to flow.

Abstract: Cross point memory array using distinct voltages. The invention is a cross point memory array that applies a first select voltage on one conductive array line, a second select voltage on a second conductive array line, the two conductive array lines uniquely defining a single memory plug. The magnitude of the select voltages depends upon whether a read operation or a write operation is occurring. Additionally, an unselect voltage is applied to the unselected conductive array lines. The unselect voltage can be applied before, after or during the selection process. The unselect voltage is approximately equal to the average of the first select voltage and the second select voltage.

Abstract: Non-volatile memory cell with a single semiconductor device per memory cell. The present invention generally allows for a plurality of memory cells to be formed on a semiconductor substrate that supports a semiconductor device. A multi-resistive state material layer that changes its resistive state between a low resistive state and a high resistive state upon application of a voltage pulse is formed above the substrate, generally at a very high temperature. While the layers fabricated between the substrate and the multi-resistive state material use materials that can withstand high temperature processing, the layers fabricated above the multi-resistive state material do not need to withstand high temperature processing.

Abstract: Providing a reference voltage to a cross point memory array. The invention is a cross point memory array and some peripheral circuitry that, when activated, provides a reference voltage to a cross point array in order to prevent unselected conductive array lines from floating to an undesired voltage. The peripheral circuitry can be activated before, after or during selection of a specific memory plug. If the peripheral circuitry is activated during selection, only the unselected conductive array lines should be brought to the reference voltage. Otherwise, all the conductive array lines can be brought to the reference voltage.

Abstract: A multi-resistive state material that uses dopants is provided. A multi-resistive state material can be used in a memory cell to store information. However, a multi-resistive state material may not have electrical properties that are appropriate for a memory device. Intentionally doping a multi-resistive state material to modify the electrical properties can, therefore, be desirable.

Abstract: Non-volatile memory cell with a single semiconductor device per memory cell. The present invention generally allows for a plurality of memory cells to be formed on a semiconductor substrate that supports a semiconductor device. A multi-resistive state material layer that changes its resistive state between a low resistive state and a high resistive state upon application of a voltage pulse is formed above the substrate, generally at a very high temperature. While the layers fabricated between the substrate and the multi-resistive state material use materials that can withstand high temperature processing, the layers fabricated above the multi-resistive state material do not need to withstand high temperature processing.

Abstract: A 2-terminal trapped charge memory device is disclosed with voltage switchable multi-level resistance. The trapped charge memory device has a trapped charge memory body sandwiched between two electrodes. The trapped charge memory body can be made of a variety of semiconducting or insulating materials of single-crystalline, poly-crystalline or amorphous structure while containing current carrier traps whose respective energy levels and degrees of carrier occupancy, modifiable by the height and width of an applied write voltage pulse, determine the resistance. The mechanism of modification can be through carrier tunneling, free carrier capturing, trap-hopping conduction or Frenkel-Poole conduction. The current carrier traps can be created with dopant varieties or an initialization procedure.

Abstract: Providing a multi-output multiplexor. The invention is multi-output multiplexor that, depending on the control signals, allows various modulating circuits to pass no voltage, pass some voltage or pass all the voltage on one of the mulitplexor's ports., A modulating circuit can be fully turned on, partially turned on, or fully turned off. In a preferred embodiment, a gate circuit is in electrical contact with ground such that when the gate circuit is turned on and its associated modulating circuit is not passing voltage, the multiplexor output associated with the modulating circuit goes to ground.

Abstract: Layouts of driver sets in a cross point memory array. Since both terminals of a memory cell in a cross point structure are typically used for selection purposes, dedicated driver sets are typically required for both x and y directions. By fabricating the cross point array above the driver circuitry, several different driver set layouts can be utilized that allow for varying designs.

Abstract: A multi-resistive state element that uses barrier electrodes is provided. If certain materials are used as electrodes, the electrodes can be used for multiple purposes. Oxides and nitrides are especially well suited for acting as a barrier layer, and possibly even an adhesion layer and a sacrificial layer.

Abstract: Cross point array with fast access time. A cross point array is driven by drivers on a semiconductor substrate. The drivers for either a single-layer cross point array or for the bottom layer of a stacked cross point array can be positioned to improve access time. Specifically, if the x-direction drivers are positioned in the middle of the x-direction conductive array lines and the y-direction drivers are positioned in the middle of the y-direction conductive array lines, the access time will be improved.

Abstract: Line drivers that fit within a specified line pitch. One method of placing line drivers completely underneath a cross point array requires splitting the line driver up so that a portion of the line drivers is on a first side of the cross point array and the other portion is on the opposite side. However, using this technique requires that the width of the drivers is no larger than the width of the memory cells that are being driven. This can be accomplished by stacking transistors such that line drivers fit within a specified line pitch, but are as long as is necessary to include all the necessary circuitry.

Abstract: A re-writable memory with multiple memory layers. Using both terminals of a memory cell in a stacked cross point structure for selection purposes allows multiple layers of conductive lines to be selected as long as there is only one memory cell that has two terminals selected. Sharing logic over multiple layers allows driver sets to be reused.

Abstract: High density NVRAM. The invention is a an array of memory cells capable of storing at least a megabit of information, each memory cell including a memory plug that includes a memory element that switches from a first resistance state to a second resistance state upon application of a first write voltage of a first polarity and reversibly switches from the second resistance state to the first resistance state upon application of a second write voltage of polarity opposite to the first polarity.

Abstract: Cross point memory array using multiple modes of operation. The invention is a cross point memory array that uses a read mode to determine the resistive state of a memory plug, a first write mode to cause the memory plug to change from a first resistive state to a second resistive state, and a second write mode to cause the memory plug to change from the second resistive state back to the first resistive state.

Abstract: Line drivers that use minimal metal layers. Line driver connections typically need to be made to various other peripheral circuits. Although multiple metal layers could be used to make all the necessary connections, it is desirable to use the fewest metal layers possible. By keeping all y-direction lines on a first layer, and most of the x-direction lines on a second layer, only two metal layers are required. Additionally, an array cut could be used that allows line drivers to reach upper conductive array lines.

Abstract: A multi-resistive state element that uses a treated interface is provided. A memory plug includes at least two electrodes that sandwich a multi-resistive state element. Using different treatments on both electrode/multi-resistive state element interfaces improves the memory properties of the entire memory device.

Abstract: A memory array with components that can withstand high temperature fabrication is provided. Some memory materials require high temperature process steps in order to achieve desired properties. During fabrication, a memory material is deposited on structures that may include metal lines and barrier layers. Such structures are then exposed to the high temperature processing steps and should be resistant to such temperatures.

Abstract: Providing a multiplexor outputting a reference voltage on unselected lines. A multiplexor that has at least one selected line and multiple unselected lines will have the unselected lines at a reference voltage. The selected line allows at least a portion of voltage to pass. Two gate circuits are used for each line, one that controls whether voltage (or a portion thereof) will pass, the other that connects the first gate circuit to a reference voltage, such as ground. In some embodiments the second gate circuit is always on, but is relatively small, such that the connection to the reference voltage has a weak effect on the output voltage. In other embodiments, the second gate circuit is only on when its associated first gate circuit is off.