摘要:
Perpendicular magnetic anisotropy (PMA) type magnetic random access memory cells are constructed with a composite PMA layer to provide a magnetic tunnel junction (MTJ) with an acceptable thermal barrier. A PMA coupling layer is deposited between a first PMA layer and a second PMA layer to form the composite PMA layer. The composite PMA layer may be incorporated in PMA type MRAM cells or in-plane type MRAM cells.
摘要:
An entropy source and a random number (RN) generator are disclosed. In one aspect, a low-energy entropy source includes a magneto-resistive (MR) element and a sensing circuit. The MR element is applied a static current and has a variable resistance determined based on magnetization of the MR element. The sensing circuit senses the resistance of the MR element and provides random values based on the sensed resistance of the MR element. In another aspect, a RN generator includes an entropy source and a post-processing module. The entropy source includes at least one MR element and provides first random values based on the at least one MR element. The post-processing module receives and processes the first random values (e.g., based on a cryptographic hash function, an error detection code, a stream cipher algorithm, etc.) and provides second random values having improved randomness characteristics.
摘要:
A method for integrating a magnetic tunnel junction (MTJ) device into an integrated circuit includes providing in a semiconductor back-end-of-line (BEOL) process flow a substrate having a first interlevel dielectric layer and at least a first metal interconnect. Over the first interlevel dielectric layer and the first metal interconnect, magnetic tunnel junction material layers are deposited. From the material layers a magnetic tunnel junction stack, coupled to the first metal interconnect, is defined using a single mask process. The magnetic tunnel junction stack is integrated into the integrated circuit.
摘要:
A circuit includes a degeneration p-channel metal-oxide-semiconductor (PMOS) transistor, a load PMOS transistor, and a clamp transistor configured to clamp a voltage applied to a resistance based memory element during a sensing operation. A gate of the load PMOS transistor is controlled by an output of an operational amplifier.
摘要:
A Multi-Level Memory Cell (MLC) using multiple Magnetic Tunnel Junction (MTJ) structures having one or more layers with varying thickness is disclosed. The multiple MTJ structures, which are vertically stacked and arranged in series, may have substantially identical area dimensions to minimize fabrication costs because one mask can be used to pattern the multiple MTJ structures. Further, varying the thicknesses associated with the one or more layers may provide the multiple MTJ structures with different switching current densities and thereby increase memory density and improve read and write operations. In one embodiment, the layers with the varying thicknesses may include tunnel barriers or magnesium oxide layers associated with the multiple MTJ structures and/or free layers associated with the multiple MTJ structures.
摘要:
Asymmetric switching is defined for magnetic bit cell elements. A magnetic bit cell for memory and other devices includes a transistor coupled to an MTJ structure. A bit line is coupled at one terminal of the bit cell to the MTJ structure. At another terminal of the bit cell, a source line is coupled to the source/drain terminal of the transistor. The bit line is driven by a bit line driver that provides a first voltage. The source line is driven by a source line driver that provides a second voltage. The second voltage is larger than the first voltage. The switching characteristics of the bit cell and MTJ structure are improved and made more reliable by one or a combination of applying the higher second voltage to the source line and/or reducing the overall parasitic resistance in the magnetic bit cell element.
摘要:
A resistance based memory sensing circuit has reference current transistors feeding a reference node and a read current transistor feeding a sense node, each transistor has a substrate body at a regular substrate voltage during a stand-by mode and biased during a sensing mode at a body bias voltage lower than the regular substrate voltage. In one option the body bias voltage is determined by a reference voltage on the reference node. The substrate body at the regular substrate voltage causes the transistors to have a regular threshold voltage, and the substrate body at the body bias voltage causes the transistors to have a sense mode threshold voltage, lower than the regular threshold voltage.
摘要:
According to an embodiment of the invention, a magnetic tunnel junction (MTJ) element includes a reference ferromagnetic layer, a storage ferromagnetic layer, and an insulating layer. The storage ferromagnetic layer includes a CoFeB sub-layer coupled to a CoFe sub-layer and/or a NiFe sub-layer through a non-magnetic sub-layer. The insulating layer is disposed between the reference and storage ferromagnetic layers.
摘要:
A magnetic tunnel junction (MTJ) device and fabrication method is disclosed. In a particular embodiment, a method of forming a magnetic tunnel junction (MTJ) device includes forming an MTJ cap layer on an MTJ structure and forming a top electrode layer over the MTJ cap layer. The top electrode layer includes a first nitrified metal.
摘要:
A computer program product estimates performance of an interconnect structure of a semiconductor integrated circuit (IC). The program product includes code executing on a computer to calculate at least one electrical characteristic of the interconnect structure based on input data accounting for multiple layers of the interconnect structure. The electrical characteristics can be capacitance, resistance, and/or inductance. The capacitance may be based upon multiple components, including a fringe capacitance component, a terminal capacitance component, and a coupling capacitance component.