Abstract: The present invention is directed to a spin transfer torque (STT) MRAM device having a perpendicular magnetic tunnel junction (MTJ) memory element. The memory element includes a perpendicular MTJ structure in between a non-magnetic seed layer and a non-magnetic cap layer. The MTJ structure comprises a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween, an anti-ferromagnetic coupling layer formed adjacent to the magnetic reference layer structure, and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. At least one of the magnetic free and reference layer structures includes a non-magnetic perpendicular enhancement layer, which improves the perpendicular anisotropy of magnetic layers adjacent thereto.

Abstract: A magnetic random access memory (MRAM) element is configured to store a state when electric current flows therethrough. The MRAM element includes a first magnetic tunnel junction (MTJ) for storing a data bit and a reference bit MTJ for storing a reference bit. The data bit MTJ and reference bit MTJ are preferred to be of identical structure that includes a magnetic free layer (FL) having a switchable magnetization with a direction that is perpendicular to a film plane. The direction of magnetization of the FL is determinative of the data bit stored in the at least one MTJ. The identical structure further includes a magnetic reference layer (RL) having a magnetization with a direction that is perpendicular to the film plane, and a magnetic pinned layer (PL) having a magnetization with a direction that is perpendicular to the film plane.

Abstract: The present invention is directed to an apparatus for initializing perpendicular magnetic tunnel junction. The apparatus comprises a permanent magnet for generating a magnetic flux; a flux concentrator made of a soft ferromagnetic material and having a base area in contact with the permanent magnet and an tip area that is smaller than the base area, thereby funneling and concentrating the magnetic flux to the tip area for emitting a magnetic field therefrom; and a means for supporting and conveying a substrate with an arrays of magnetic tunnel junctions formed therein to traverse the magnetic field in close proximity to the tip area. The apparatus may further include at least one of the following: a substrate heater, a flux containment structure coupled to the permanent magnet, and a magnetic imaging plate disposed in proximity to the substrate on the opposite side from the flux concentrator.

Abstract: The present invention is directed to a method for reading and writing an STT-MRAM multi-level cell (MLC), which includes a plurality of memory elements coupled in series. The method detects the resistance states of individual memory elements in an MLC by sequentially writing at least one of the plurality of memory element to the low resistance state in order of ascending write current threshold. If a written element switches the resistance state thereof after the write step, then the written element was in the high resistance state prior to the write step. Otherwise, the written element was in the low resistance state prior to the write step. The switching of the resistance state can be ascertained by comparing the resistance or voltage values of the plurality of memory elements before and after writing each of the plurality of memory elements in accordance with the embodiments of the present invention.

Abstract: The current invention relates to the method to achieve re-focusable vision, including re-focusable stereo vision, with detecting the re-focusing event from a human eye. The method comprises utilizing optical and electrical sensing apparatus to detect the physiological change of viewer's eye without viewer's active participation or physical action, and retrieving the intended focus depth information of the viewer from such physiological information to update the visual impression perceived by the viewer that matches the intended focus depth, to achieve a re-focusable vision. The sensing apparatus includes both “glass” type and “contact-lens” type of see-through substrates that contain optical and electrical components that are necessary for obtaining the physiological information of viewer's eye and controlling the visual impression that the viewer perceives.

Abstract: The present invention is directed to an MTJ memory element including a magnetic free layer structure which comprises one or more magnetic free layers that have a same variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure comprising a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated therefrom by a perpendicular enhancement layer with the first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the perpendicular enhancement layer; and a magnetic fixed layer comprising first and second magnetic fixed sublayers with the second magnetic fixed sublayer formed adjacent to the anti-ferromagnetic

Abstract: A spin transfer torque magnetic random access memory (STTMRAM) element comprises a reference layer, which can be a single layer structure or a synthetic multi-layer structure, formed on a substrate, with a fixed perpendicular magnetic component. A junction layer is formed on top of the reference layer and a free layer is formed on top of the junction layer with a perpendicular magnetic orientation, at substantially its center of the free layer and switchable. A tuning layer is formed on top of the free layer and a fixed layer is formed on top of the tuning layer, the fixed layer has a fixed perpendicular magnetic component opposite to that of the reference layer. The magnetic orientation of the free layer switches relative to that of the reference layer. The perpendicular magnetic components of the fixed layer and the reference layer substantially cancel each other and the free layer has an in-plane edge magnetization field.

Abstract: A spin-transfer torque magnetic random access memory (STTMRAM) element includes a composite fixed layer formed on top of a substrate and a tunnel layer formed upon the fixed layer and a composite free layer formed upon the tunnel barrier layer. The magnetization direction of each of the composite free layer and fixed layer being substantially perpendicular to the plane of the substrate. The composite layers are made of multiple repeats of a bilayer unit which consists of a non-magnetic insulating layer and magnetic layer with thicknesses adjusted in a range that makes the magnetization having a preferred direction perpendicular to film plane.

Abstract: The current invention relates to the method to achieve artificial vision with using flexible substrate based light emitting arrays, or optical passage arrays, to project image upon the retina of a human eye. Further, it relates to the method to detect the real-time focal length change of the eye-lens and modify the flexible substrate curvature and distance from the eye to vary global angle configurations of light beams that go into the eye to produce images on the retina at various focus depth of the eye to achieve re-focusable artificial vision.

Abstract: A spin-transfer torque magnetic random access memory (STTMRAM) element includes a composite fixed layer formed on top of a substrate and a tunnel layer formed upon the fixed layer and a composite free layer formed upon the tunnel barrier layer. The magnetization direction of each of the composite free layer and fixed layer being substantially perpendicular to the plane of the substrate. The composite layers are made of multiple repeats of a bilayer unit which consists of a non-magnetic insulating layer and magnetic layer with thicknesses adjusted in a range that makes the magnetization having a preferred direction perpendicular to film plane.

Abstract: A spin transfer oscillator with a seed/SIL/spacer/FGL/capping configuration is disclosed with a composite seed layer made of Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (A1/A2)X laminated spin injection layer (SIL). Field generation layer (FGL) is made of a high Bs material such FeCo. Alternatively, the STO has a seed/FGL/spacer/SIL/capping configuration. The SIL may include a FeCo layer that is exchanged coupled with the (A1/A2)X laminate (x is 5 to 50) to improve robustness. The FGL may include an (A1/A2)Y laminate (y=5 to 30) exchange coupled with the high Bs layer to enable easier oscillations. A1 may be one of Co, CoFe, or CoFeR where R is a metal, and A2 is one of Ni, NiCo, or NiFe. The STO may be formed between a main pole and trailing shield in a write head.

Abstract: Embodiments of the invention are described that use a thin metallic hard mask, which can be a bi-layer film, to increase the incident IBE angle for MTJ sidewall cleaning without losing the process margin for the subsequent interconnection process. The patterned metallic hard mask pads also serve as the top electrode for the MTJ cells. Using a thin metallic hard mask is possible when the hard mask material acts as a CMP stopper without substantial loss of thickness. In the first embodiment, the single layer hard mask is preferably ruthenium. In the second embodiment, the lower layer of the bi-layer hard mask is preferably ruthenium. The wafer is preferably rotated during the IBE process for uniform etching. A capping layer under the hard mask is preferably used as the etch stopper during hard mask etch process in order not to damage or etch through the upper magnetic layer.

Abstract: A spin transfer torque magnetic random access memory (STTMRAM) element and a method of manufacturing the same is disclosed having a free sub-layer structure with enhanced internal stiffness. A first free sub-layer is deposited, the first free sub-layer being made partially of boron (B), annealing is performed of the STTMRAM element at a first temperature after depositing the first free sub-layer to reduce the B content at an interface between the first free sub-layer and the barrier layer, the annealing causing a second free sub-layer to be formed on top of the first free sub-layer and being made partially of B, the amount of B of the second free sub-layer being greater than the amount of B in the first free sub-layer.

Abstract: The present invention is directed to a spin transfer torque (STT) MRAM device having a perpendicular magnetic tunnel junction (MTJ) memory element. The memory element includes a perpendicular MTJ structure in between a non-magnetic seed layer and a non-magnetic cap layer. The MTJ structure comprises a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween, an anti-ferromagnetic coupling layer formed adjacent to the magnetic reference layer structure, and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. At least one of the magnetic free and reference layer structures includes a non-magnetic perpendicular enhancement layer, which improves the perpendicular anisotropy of magnetic layers adjacent thereto.

Abstract: Chip packages are described with soft-magnetic shields that are included inside or attached externally to the package containing a MRAM chip. In one group of embodiments a single shield with vias for bonding wires is affixed to the surface of the MRAM chip having the contact pads. The limitation of shield to chip distance due to bonding wire is eliminated by VIA holes according to the invention which achieves minimal spacing between the shield and chip. A second shield without vias can be positioned on the opposite side of the chip from the first shield. In one group of embodiments a hardened ferro-fluid shield can be the only shield or the structure can include a shield with or without vias. One group of embodiments includes an external shield with vias for solder access to the package contact pads affixed to the outer surface of the package.

Abstract: The present invention is directed to an MTJ memory element including a magnetic free layer structure which comprises one or more magnetic free layers that have a same variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure comprising a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated therefrom by a perpendicular enhancement layer with the first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the perpendicular enhancement layer; and a magnetic fixed layer comprising first and second magnetic fixed sublayers with the second magnetic fixed sublayer formed adjacent to the anti-ferromagnetic

Abstract: A spin transfer torque magnetic random access memory (STTMRAM) element and a method of manufacturing the same is disclosed having a free sub-layer structure with enhanced internal stiffness. A first free sub-layer is deposited, the first free sub-layer being made partially of boron (B), annealing is performed of the STTMRAM element at a first temperature after depositing the first free sub-layer to reduce the B content at an interface between the first free sub-layer and the barrier layer, the annealing causing a second free sub-layer to be formed on top of the first free sub-layer and being made partially of B, the amount of B of the second free sub-layer being greater than the amount of B in the first free sub-layer.

Abstract: The performance of an MR device has been improved by inserting one or more Magneto-Resistance Enhancing Layers (MRELs) into approximately the center of one or more of the magnetic layers such as an inner pinned (AP1) layer, spin injection layer (SIL), field generation layer (FGL), and a free layer. An MREL is a layer of a low band gap, high electron mobility semiconductor such as ZnO or a semimetal such as Bi. The MREL may further comprise a first conductive layer that contacts a bottom surface of the semiconductor or semimetal layer, and a second conductive layer that contacts a top surface of the semiconductor or semimetal layer.

Abstract: The present invention is directed to a method for reading and writing an STT-MRAM multi-level cell (MLC), which includes a plurality of memory elements coupled in series. The method detects the resistance states of individual memory elements in an MLC by sequentially writing at least one of the plurality of memory element to the low resistance state in order of ascending write current threshold. If a written element switches the resistance state thereof after the write step, then the written element was in the high resistance state prior to the write step. Otherwise, the written element was in the low resistance state prior to the write step. The switching of the resistance state can be ascertained by comparing the resistance or voltage values of the plurality of memory elements before and after writing each of the plurality of memory elements in accordance with the embodiments of the present invention.

Abstract: The present invention is directed to a method for manufacturing spin transfer torque magnetic random access memory (STTMRAM) devices. The method, which utilizes in-situ annealing and etch-back of the magnetic tunnel junction (MTJ) film stack, comprises the steps of depositing a barrier layer on top of a bottom magnetic layer and then depositing an interface magnetic layer on top of the barrier layer to form an MTJ film stack; annealing the MTJ film stack at a first temperature and then cool the MTJ film stack to a second temperature lower than the first temperature; etching away a top portion of the interface magnetic layer; and depositing at least one top layer on top of the etched interface magnetic layer. The method may further include the step of annealing the MTJ film stack at a third temperature between the first and second temperature after the step of depositing at least one top layer.