Abstract:
Techniques are disclosed for forming integrated circuit structures including a magnetic tunnel junction (MTJ), such as spin-transfer torque memory (STTM) devices, having magnetic contacts. The techniques include incorporating an additional magnetic layer (e.g., a layer that is similar or identical to that of the magnetic contact layer) such that the additional magnetic layer is coupled antiferromagnetically (or in a substantially antiparallel manner). The additional magnetic layer can help balance the magnetic field of the magnetic contact layer to limit parasitic fringing fields that would otherwise be caused by the magnetic contact layer. The additional magnetic layer may be antiferromagnetically coupled to the magnetic contact layer by, for example, including a nonmagnetic spacer layer between the two magnetic layers, thereby creating a synthetic antiferromagnet (SAF). The techniques can benefit, for example, magnetic contacts having magnetic directions that are substantially in-line or substantially in-plane with the layers of the MTJ stack.
Abstract:
Techniques are disclosed for fabricating a self-aligned spin-transfer torque memory (STTM) device with a dot-contacted free magnetic layer. In some embodiments, the disclosed STTM device includes a first dielectric spacer covering sidewalls of an electrically conductive hardmask layer that is patterned to provide an electronic contact for the STTM's free magnetic layer. The hardmask contact can be narrower than the free magnetic layer. The first dielectric spacer can be utilized in patterning the STTM's fixed magnetic layer. In some embodiments, the STTM further includes an optional second dielectric spacer covering sidewalls of its free magnetic layer. The second dielectric spacer can be utilized in patterning the STTM's fixed magnetic layer and may serve, at least in part, to protect the sidewalls of the free magnetic layer from redepositing of etch byproducts during such patterning, thereby preventing electrical shorting between the fixed magnetic layer and the free magnetic layer.
Abstract:
Described herein are apparatuses, systems, and methods associated with a memory circuit that includes memory cells having respective threshold switches. The memory cells may include a selector transistor with a gate terminal coupled to a word line to receive a word line signal, a drain terminal coupled to a bit line to receive a bit line signal, and a source terminal coupled to a first terminal of the threshold switch. The threshold switch may switch from a high resistance state to a low resistance state when a voltage across the first terminal and a second terminal exceeds a threshold voltage and may remain in the low resistance state after switching when the voltage across the first and second terminals is equal to or greater than a holding voltage that is less than the threshold voltage. Other embodiments may be described and claimed.
Abstract:
Techniques are disclosed for forming integrated circuit structures including a magnetic tunnel junction (MTJ), such as spin-transfer torque memory (STTM) devices, having magnetic contacts. The techniques include incorporating an additional magnetic layer (e.g., a layer that is similar or identical to that of the magnetic contact layer) such that the additional magnetic layer is coupled antiferromagnetically (or in a substantially antiparallel manner). The additional magnetic layer can help balance the magnetic field of the magnetic contact layer to limit parasitic fringing fields that would otherwise be caused by the magnetic contact layer. The additional magnetic layer may be antiferromagnetically coupled to the magnetic contact layer by, for example, including a nonmagnetic spacer layer between the two magnetic layers, thereby creating a synthetic antiferromagnet (SAF). The techniques can benefit, for example, magnetic contacts having magnetic directions that are substantially in-line or substantially in-plane with the layers of the MTJ stack.
Abstract:
Techniques are disclosed for forming non-planar resistive memory cells, such as non-planar resistive random-access memory (ReRAM or RRAM) cells. The techniques can be used to reduce forming voltage requirements and/or resistances involved (such as the resistance during the low-resistance state) relative to planar resistive memory cells for a given memory cell space. The non-planar resistive memory cell includes a first electrode, a second electrode, and a switching layer disposed between the first and second electrodes. The second electrode may be substantially between opposing portions of the switching layer, and the first electrode may be substantially adjacent to at least two sides of the switching layer, after the non-planar resistive memory cell is formed. In some cases, an oxygen exchange layer (OEL) may be disposed between the switching layer and one of the first and second electrodes to, for example, increase flexibility in incorporating materials in the cell.
Abstract:
A perpendicular spin transfer torque memory (pSTTM) device incorporates a magnetic tunnel junction (MTJ) device having a free magnetic stack that includes a plurality of magnetic layers interleaved with a plurality of non-magnetic insert layers. The layers are arranged such that the topmost and bottommost layers are magnetic layers. The stacked design decreases the damping of the MTJ free magnetic stack, beneficially reducing the write current required to write to the pSTTM device. The stacked design further increases the interface anisotropy, thereby beneficially improving the stability of the pSTTM device. The non-magnetic interface layer may include tantalum, molybdenum, tungsten, hafnium, or iridium, or a binary alloy containing at least two of tantalum, molybdenum, tungsten hafnium, or iridium.
Abstract:
Technologies for manufacturing spin transfer torque memory (STTM) elements are disclosed. In some embodiments, the technologies include methods for interrupting the electrical continuity of a re-deposited layer that may form on one or more sidewalls of an STTM element during its formation. Devices and systems including such STTM elements are also described.
Abstract:
Techniques are disclosed for enhancing performance of a perpendicular magnetic tunnel junction (MTJ) by implementing an additional ferromagnetic layer therein. The additional ferromagnetic layer can be implemented, for example, in or otherwise proximate either the fixed ferromagnetic layer or the free ferromagnetic layer of the perpendicular MTJ. In some embodiments, the additional ferromagnetic layer is implemented with a non-magnetic spacer, wherein the thickness of the additional ferromagnetic layer and/or spacer can be adjusted to sufficiently balance the energy barrier between parallel and anti-parallel states of the perpendicular MTJ. In some embodiments, the additional ferromagnetic layer is configured such that its magnetization is opposite that of the fixed ferromagnetic layer.
Abstract:
Techniques are disclosed for forming integrated circuit (IC) devices that include ferroelectric field-effect transistors (FE-FETs) having a top gate and a bottom gate (or, generally, a dual-gate configuration). The disclosed FE-FET devices may be formed in the back end of the IC structure and may be implemented with various materials that exhibit ferroelectric properties when processed at temperatures within the thermal budget of the back-end processing. The disclosed back-end FE-FET devices can achieve greater than two resistance states, depending on the direction of poling of the top and bottom gates, thereby enabling the formation of 3-state and 4-state memory devices, for example. Additionally, as will be appreciated in light of this disclosure, the disclosed back-end FE-FET devices can free up floor space in the front-end, thereby providing space for additional devices in the front-end.
Abstract:
A perpendicular spin transfer torque memory (pSTTM) device incorporates a magnetic tunnel junction (MTJ) device having a free magnetic stack and a fixed magnetic stack separated by a dielectric tunneling layer. The free magnetic stack includes an uppermost magnetic layer that is at least partially covered by a cap layer. The cap layer is at least partially covered by a protective layer containing at least one of: ruthenium (Ru); cobalt/iron/boron (CoFeB); molybdenum (Mo); cobalt (Co); tungsten (W); or platinum (Pt). The protective layer is at least partially covered by a cap metal layer which may form a portion of MTJ electrode. The protective layer minimizes the occurrence of physical and/or chemical attack of the cap layer by the materials used in the cap metal layer, beneficially improving the interface anisotropy of the