Abstract:
Certain aspects provide a circuit for in-memory computation. The circuit generally includes an in-memory computation array having a plurality of computation circuits, each of the computation circuits being configured to perform a dot product computation. In certain aspects, each of the computation circuits includes a memory cell, a capacitive element, a precharge transistor coupled between an output of the memory cell and the capacitive element, and a read transistor coupled between a read bit line (RBL) and the capacitive element.
Abstract:
A material stack of a synthetic anti-ferromagnetic (SAF) reference layer of a perpendicular magnetic tunnel junction (MTJ) may include an SAF coupling layer. The material stack may also include and an amorphous spacer layer on the SAF coupling layer. The amorphous spacer layer may include an alloy or multilayer of tantalum and cobalt or tantalum and iron or cobalt and iron and tantalum. The amorphous spacer layer may also include a treated surface of the SAF coupling layer.
Abstract:
A complementary bit cell includes a first magnetic tunnel junction (MTJ) device having a free layer coupled to a first access transistor and having a pinned layer coupled to a bit line. The complementary bit cell also includes a second MTJ device having a free layer coupled to the same bit line and having a pinned layer coupled to a second access transistor.
Abstract:
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.
Abstract:
An apparatus includes a perpendicular magnetic anisotropy magnetic tunnel junction (pMTJ) device. The pMTJ device includes a storage layer and a reference layer. The reference layer includes a portion configured to produce a ferrimagnetic effect. The portion includes a first layer, a second layer, and a third layer. The second layer is configured to antiferromagnetically (AF) couple the first layer and the third layer during operation of the pMTJ device.
Abstract:
A complementary bit cell includes a first magnetic tunnel junction (MTJ) device having a free layer coupled to a first access transistor and having a pinned layer coupled to a bit line. The complementary bit cell also includes a second MTJ device having a free layer coupled to the same bit line and having a pinned layer coupled to a second access transistor.
Abstract:
A magnetic tunnel junction (MTJ) device includes a pinned layer, a tunnel barrier layer on the pinned layer, and a free layer on the tunnel barrier layer. The MTJ device also includes a perpendicular magnetic anisotropic (PMA) enhancement layer on the free layer, a capping layer on the PMA enhancement layer, and a conductive path electrically shorting the capping layer, the PMA enhancement layer and the free layer. A method of fabricating a perpendicular magnetic tunnel junction (pMTJ) device includes forming a capping layer, a perpendicular magnetic anisotropic (PMA) enhancement layer and a free layer. The method also includes forming a conductive layer to short the capping layer, the PMA enhancement layer and the free layer.
Abstract:
An STT magnetic memory includes adjacent columns of STT magnetic memory elements having a top electrode and a bottom electrode. A shared bit line is coupled to the top electrode of the STT magnetic memory elements in at least two of the adjacent columns. The bottom electrodes of the STT magnetic memory elements of one of the adjacent columns are selectively coupled to one source line, and the bottom electrodes of the STT magnetic memory elements of another among the adjacent columns are selectively coupled to another source line.
Abstract:
One feature pertains to a method of implementing a physically unclonable function (PUF). The method includes exposing an array of magnetoresistive random access memory (MRAM) cells to an orthogonal external magnetic field. The MRAM cells are each configured to represent one of a first logical state and a second logical state, and the orthogonal external magnetic field is oriented in an orthogonal direction to an easy axis of a free layer of the MRAM cells to place the MRAM cells in a neutral logical state that is not the first logical state or the second logical state. The method further includes removing the orthogonal external magnetic field to place each of the MRAM cells of the array randomly in either the first logical state or the second logical state.
Abstract:
A first write driver applies a first voltage above a fixed potential to a first terminal. A second write driver applies a second voltage that is higher above the fixed potential than the first voltage to a second terminal. There is at least one magnetic tunnel junction (MTJ) structure coupled at the first terminal at a first side to the first write driver and coupled at the second terminal at a second side to the second write driver. The first side of the MTJ structure receives the first voltage and the second side of the MTJ structure receives a ground voltage to change from a first state to a second state. The second side of the MTJ structure receives the second voltage and the first side of the MTJ structure receives the ground voltage to change from the second state to the first state.