Abstract: In a spin-torque magnetic random access memory (MRAM) that includes local source lines, auto-booting of the word line is used to reduce power consumption by reusing charge already present from driving a plurality of bit lines during writing operations. Auto-booting is accomplished by first driving the word line to a first word line voltage. After such driving, the word line isolated. Subsequent driving of the plurality of bit lines that are capacitively coupled to the word line causes the word line voltage to be increased to a level desired to allow sufficient current to flow through a selected memory cell to write information into the selected memory cell. Additional embodiments include the use of a supplemental voltage provider that is able to further boost or hold the isolated word line at the needed voltage level.

Abstract: Techniques for recovering preprogrammed data from non-volatile memory are provided that include majority voting and/or use of one or more levels of ECC correction. Embodiments include storage of multiple copies of the data where ECC correction is performed before and after majority voting with respect to the multiple copies. Multiple levels of ECC correction can also be performed where one level of ECC is performed at the local level (e.g. on-chip), whereas another level of ECC correction is performed at a system level.

Abstract: Structures and methods are disclosed for shielding magnetically sensitive components. One structure includes a substrate, a bottom shield deposited on the substrate, a magnetoresistive semiconductor device having a first surface and a second surface opposing the first surface, the first surface of the magnetoresistive semiconductor device deposited on the bottom shield, a top shield deposited on the second surface of the magnetoresistive semiconductor device, the top shield having a window for accessing the magnetoresistive semiconductor device, and a plurality of interconnects that connect the magnetoresistive semiconductor device to a plurality of conductive elements.

Abstract: Precharging circuits and techniques are presented for use with magnetic memory devices in order to speed up access to the memory cells for reading and writing. Including precharging in the sense amplifiers used to access the memory cells enables self-referenced read operations to be completed more quickly than is possible without precharging. Similarly, precharging can also be used in conjunction with write-back operations in order to allow the data state stored by magnetic tunnel junctions included in the memory cells to be changed more rapidly.

Abstract: A magnetic field sensor includes built-in self-test coils in a configuration to provide magnetic field stimulation along three axes, with a high field factor, and thus, reduce a power budget of the sensor and physical size of the self-test coils. The magnetic field sensor comprises a first bridge circuit including a plurality of sense elements configured to sense a magnetic field. The magnetic field sensor further comprises re-configurable self-test current lines coupled to a self-test source to perform high field, high power wafer and die level testing and trim, as well as low power in-situ characterization and calibration of the sensor. The self-test current lines may be routed to form a coil with multiple turns around the TMR elements.

Abstract: A magnetoresistive memory device that stores data in the synthetic antiferromagnet (SAF) included in each spin-torque memory cell provides for more robust data storage. In normal operation, the memory cells use the free portion of the memory cell for data storage. Techniques for storing data in the reference portions of memory cells are presented, where an unbalanced SAF that includes ferromagnetic layers having different magnetic moments is used to lower the switching barrier for the SAF and allow for writing data values to the SAF using lower currents and magnetic fields than would be required for a balanced SAF.

Abstract: The present disclosure is drawn to, among other things, a method of forming a semiconductor shield from a stock material having a thickness. In some aspects the methods includes providing a first layer of material on a first surface of the stock material, wherein at least a portion of the first layer of material includes a first window that exposes a portion of the first surface; providing a second layer of material on a second surface of the stock material, wherein the second surface of the stock material is spaced from the first surface by the thickness of the stock material, and wherein at least portion of the second layer of material includes a second window that exposes a portion of the second surface; and selectively removing a portion of the stock material exposed at the first or second windows, wherein the portion removed includes less than an entirety of the thickness of the stock material.

Abstract: Higher word line voltages facilitate write operations in spin-torque magnetic memory devices, but overdriving the gate of a selection transistor with such higher word line voltages can damage the selection transistor if the gate-to-source voltage for the selection transistor is too high. Therefore in order to support the word line voltage needed on the gate of the select transistor for an up-current write operation without exceeding limits on the gate-to-source voltage for the select transistor, the gate of the selection transistor can be driven in a two-step process. The gate of the selection transistor is first driven to a lower voltage within the limits of the gate-to-source voltage for the transistor when the source of the transistor is grounded or at a voltage near ground. A voltage is then applied across the memory cell, which results in the source of the selection transistor being raised above its initial ground or near-ground state.

Abstract: The present disclosure is directed to exemplary methods of manufacturing a magnetoresistive device. In one aspect, a method may include forming one or more regions of a magnetoresistive stack on a substrate, wherein the substrate includes at least one electronic device. The method also may include performing a sole annealing process on the substrate having the one or more magnetoresistive regions formed thereon, wherein the sole annealing process is performed at a first minimum temperature. Subsequent to performing the sole annealing process, the method may include patterning or etching at least a portion of the magnetoresistive stack. Moreover, subsequent to the step of patterning or etching the portion of the magnetoresistive stack, the method may include performing all additional processing on the substrate at a second temperature below the first minimum temperature.

Abstract: A magnetic field sensor includes a plurality of transducer legs coupled together as a first circuit to sense a magnetic field, wherein each transducer leg comprises a plurality of magnetoresistance sense elements. The magnetic field sensor also includes a second circuit including a first plurality of current lines, wherein each current line of the first plurality of current lines is adjacent to a corresponding plurality of magnetoresistance sense elements of a transducer leg of the plurality of transducer legs. When at least one current line of the first plurality of current lines is energized, a magnetization of each magnetoresistance sense element of the transducer leg is aligned in a first direction or a second direction opposite to the first direction. A routing pattern of the at least one current line is configured to generate an equal population of magnetoresistance sense elements with magnetization aligned in the first and second directions.

Abstract: A memory having a delayed write-back to the array of data corresponding to a previously opened page allows delays associated with write-back operations to be avoided. After an initial activation opens a first page and the read/write operations for that page are complete, write-back of the open page to the array of memory cells is delayed until after completion of a subsequent activate operation that opens a new page. Techniques to force a write-back in the absence of another activate operation are also disclosed.

Abstract: A magnetoresistive memory device that stores data in the reference portion of spin-torque memory cells provides for more robust data storage. In normal operation, the memory cells use the free portion of the memory cell for data storage. Techniques for storing data in the reference portions of memory cells are presented, along with techniques for recovering data stored in the reference portions of memory cells.

Abstract: In some examples, a memory device is configured with non-volatile memory array(s) having one or more associated volatile memory arrays. The memory device may include a non-destructive write mode configured to prevent access to the non-volatile memory array(s) during an initiation or calibration sequence performed by the memory device or an electronic device associated with the memory device to calibrate read and write access timing associated with the memory device.

Abstract: Techniques are presented for ensuring alignment marks are available for use and patterning magnetoresistive devices following the deposition of layers used to form the magnetoresistive devices. In some cases, the plurality of layers corresponding to the magnetoresistive devices are selectively etched in order to expose the underlying alignment marks, whereas in other embodiments, the deposition of the plurality of layers is controlled by deposition tool tabs that prevent the materials from obscuring the underlying alignment marks.

Abstract: An apparatus used in a self-referenced read of a memory bit cell includes circuitry including a plurality of transistors that includes an NMOS-follower transistor for applying a read voltage to a first end of the bit cell. An offset current is applied by an offset current transistor. A transmission gate allows for isolation of a capacitor used to store a sample voltage corresponding to the read voltage applied across the memory bit cell.

Abstract: A semiconductor process integrates three bridge circuits, each include magnetoresistive sensors coupled as a Wheatstone bridge on a single chip to sense a magnetic field in three orthogonal directions. The process includes various deposition and etch steps forming the magnetoresistive sensors and a plurality of flux guides on one of the three bridge circuits for transferring a “Z” axis magnetic field onto sensors orientated in the XY plane.

Abstract: In some examples, a memory device may be configured to store data in either an original or an inverted state based at least in part on a state associated with one or more shorted bit cells. For instance, the memory device may be configured to identify a shorted bit cell within a memory array and to store the data in the memory array, such that a state of the data bit stored in the shorted bit cell matches the state associated with the shorted bit cell.

Abstract: Structures and methods are disclosed for shielding magnetically sensitive components. One structure includes a substrate, a bottom shield deposited on the substrate, a magnetoresistive semiconductor device having a first surface and a second surface opposing the first surface, the first surface of the magnetoresistive semiconductor device deposited on the bottom shield, a top shield deposited on the second surface of the magnetoresistive semiconductor device, the top shield having a window for accessing the magnetoresistive semiconductor device, and a plurality of interconnects that connect the magnetoresistive semiconductor device to a plurality of conductive elements.

Abstract: A magnetoresistive element (e.g., a spin-torque magnetoresistive memory element) includes a fixed magnetic layer, a free magnetic layer, having a high-iron alloy interface region located along a surface of the free magnetic layer, wherein the high-iron alloy interface region has at least 50% iron by atomic composition, and a first dielectric, disposed between the fixed magnetic layer and the free magnetic layer. The magnetoresistive element further includes a second dielectric, having a first surface that is in contact with the surface of the free magnetic layer, and an electrode, disposed between the second dielectric and a conductor. The electrode includes: (i) a non-ferromagnetic portion having a surface that is in contact with a second surface of the second dielectric, and (ii) a second portion having at least one ferromagnetic material disposed between the non-ferromagnetic portion of the electrode and the conductor.

Abstract: Apparatus, methods, and systems are disclosed for performing bit error correction on a data stream. In some aspects, the described systems and methods may include a plurality of memory devices, a first interface, and a field programmable gate array. The field programmable gate array may include a memory controller and a plurality of re-programmable gates. At least one of the re-programmable gates may be configured as a read-only memory (ROM) to store a syndrome decode memory table, wherein the syndrome decode memory table may be configured to perform bit error correction on the data stream being read and/or written to at least one memory device of the plurality of memory devices via the first interface.