Abstract:
Provided are resistive random access memory (ReRAM) cells having diffusion barrier layers formed from various materials, such as beryllium oxide or titanium silicon nitrides. Resistive switching layers used in ReRAM cells often need to have at least one inert interface such that substantially no materials pass through this interface. The other (reactive) interface may be used to introduce and remove defects from the resistive switching layers causing the switching. While some electrode materials, such as platinum and doped polysilicon, may form inert interfaces, these materials are often difficult to integrate. To expand electrode material options, a diffusion barrier layer is disposed between an electrode and a resistive switching layer and forms the inert interface with the resistive switching layer. In some embodiments, tantalum nitride and titanium nitride may be used for electrodes separated by such diffusion barrier layers.
Abstract:
Provided are resistive random access memory (ReRAM) cells having diffusion barrier layers formed from various materials, such as beryllium oxide or titanium silicon nitrides. Resistive switching layers used in ReRAM cells often need to have at least one inert interface such that substantially no materials pass through this interface. The other (reactive) interface may be used to introduce and remove defects from the resistive switching layers causing the switching. While some electrode materials, such as platinum and doped polysilicon, may form inert interfaces, these materials are often difficult to integrate. To expand electrode material options, a diffusion barrier layer is disposed between an electrode and a resistive switching layer and forms the inert interface with the resistive switching layer. In some embodiments, tantalum nitride and titanium nitride may be used for electrodes separated by such diffusion barrier layers.
Abstract:
Embodiments of the invention generally relate to a resistive switching nonvolatile memory device having an interface layer structure disposed between at least one of the electrodes and a variable resistance layer formed in the nonvolatile memory device, and a method of forming the same. Typically, resistive switching memory elements may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices, such as digital cameras, mobile telephones, handheld computers, and music players. In one configuration of the resistive switching nonvolatile memory device, the interface layer structure comprises a passivation region, an interface coupling region, and/or a variable resistance layer interface region that are configured to adjust the nonvolatile memory device's performance, such as lowering the formed device's switching currents and reducing the device's forming voltage, and reducing the performance variation from one formed device to another.
Abstract:
Measuring current-voltage (I-V) characteristics of a solar cell using a lamp that emits light, a substrate that includes a plurality of solar cells, a positive electrode attached to the solar cells, and a negative electrode peripherally deposited around each of the solar cells and connected to a common ground, an articulation platform coupled to the substrate, a multi-probe switching matrix or a Z-stage device, a programmable switch box coupled to the multi-probe switching matrix or Z-stage device and selectively articulating the probes by raising the probes until in contact with at least one of the positive electrode and the negative electrode and lowering the probes until contact is lost with at least one of the positive electrode and the negative electrode, a source meter coupled to the programmable switch box and measuring the I-V characteristics of the substrate.
Abstract:
Embodiments of the invention generally relate to nonvolatile memory devices and methods for manufacturing such memory devices. The methods for forming improved memory devices, such as a ReRAM cells, provide optimized, atomic layer deposition (ALD) processes for forming a metal oxide film stack having a metal oxide buffer layer disposed on or over a metal oxide bulk layer. The metal oxide bulk layer contains a metal-rich oxide material and the metal oxide buffer layer contains a metal-poor oxide material. The metal oxide bulk layer is less electrically resistive than the metal oxide buffer layer since the metal oxide bulk layer is less oxidized or more metallic than the metal oxide buffer layer. In one example, the metal oxide bulk layer contains a metal-rich hafnium oxide material and the metal oxide buffer layer contains a metal-poor zirconium oxide material.
Abstract:
According to various embodiments, a resistive-switching memory element and memory element array that uses a bipolar switching includes a select element comprising only a single diode that is not a Zener diode. The resistive-switching memory elements described herein can switch even when a switching voltage less than the breakdown voltage of the diode is applied in the reverse-bias direction of the diode. The memory elements are able to switch during the very brief period when a transient pulse voltage is visible to the memory element, and therefore can use a single diode per memory cell.
Abstract:
A resistor structure incorporated into a resistive switching memory cell with improved performance and lifetime is provided. The resistor structure may be a two-terminal structure designed to reduce the maximum current flowing through a memory cell. A method is also provided for making such a memory cell. The method includes depositing a resistor structure and depositing a variable resistance layer of a resistive switching memory cell of the memory cell, where the resistor structure is disposed in series with the variable resistance layer to limit the switching current of the memory cell. The incorporation of the resistor structure is very useful in obtaining desirable levels of switching currents that meet the switching specification of various types of memory cells. The memory cells may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices.
Abstract:
A resistive switching memory device can include three or more electrodes interfacing a switching layer, including a top electrode, a bottom electrode, and a side electrode. The top and bottom electrodes can be used for forming conductive filaments and for reading the memory device. The side electrode can be used to control the resistance state of the switching layer.
Abstract:
Provided are methods of fabricating memory cells such as resistive random access memory (ReRAM) cells. A method involves forming a first layer including two high-k dielectric materials such that one material has a higher dielectric constant than the other material. In some embodiments, hafnium oxide and titanium oxide form the first layer. The higher-k material may be present at a lower concentration. In some embodiments, a concentration ratio of these two high-k materials is between about 3 and 7. The first layer may be formed using atomic layer deposition. The first layer is then annealed in an oxygen-containing environment. The method may proceed with forming a second layer including a low-k dielectric material, such as silicon oxide, and forming an electrode. After forming the electrode, the memory cell is annealed in a nitrogen containing environment. The nitrogen anneal may be performed at a higher temperature than the oxygen anneal.
Abstract:
Provided are resistive random access memory (ReRAM) cells with embedded resistors and methods of fabricating these cells. An embedded resistor may include a metal silicon nitride of a first metal and may be doped with a second metal, which is different from the first metal. The second metal may have less affinity to form covalent bonds with nitrogen than the first metal. As such, the second metal may be unbound and more mobile in the embedded resistor that the first metal. The second metal may help establishing conductive paths in the embedded resistor in addition to the metal nitride resulting in more a stable resistivity despite changing potential applies to the ReRAM cell. In other words, the embedded resistor having such composition will have more linear I-V performance. The concentration of the second metal in the embedded resistor may be substantially less than the concentration of the first metal.