Abstract: A “toggling” type of magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate with each memory stack having a plurality of toggle memory cells stacked along the Z axis. Each stack is located at an intersection region between the two orthogonal write lines. The cells are stacked in pairs, with the cells in each pair having their easy axes of magnetization aligned substantially parallel to one another and nonparallel with the X and Y axes. The cells in each pair have their free layers magnetically biased in opposite directions. Because the free layer of each cell in a pair is biased in a direction opposite to the bias direction of the free layer of the other cell, one cell in a pair can be toggle written without toggle writing the other cell in the pair. The bias fields on the free layers reduces the required switching field for each cell, which results in less write current and a lower-power toggling MRAM.

Abstract: A magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate, with each memory stack having two memory cells stacked along the Z axis and each memory cell having an associated biasing layer. Each biasing layer reduces the switching field of its associated cell by applying a biasing field along the hard-axis of magnetization of the free layer of its associated cell. The free layers in the two cells in each stack have their in-plane easy axes of magnetization aligned parallel to one another. Each biasing layer has its in-plane magnetization direction oriented perpendicular to the easy axis of magnetization (and thus parallel to the hard axis) of the free layer in its associated cell. The hard-axis biasing fields generated by the two biasing layers are in opposite directions.

Abstract: A multiple-memory-layer magnetic random access memory (MRAM) has multiple memory layers arranged as pairs and stacked on a substrate. The first memory layer in the pair comprises a plurality of rows of memory cells located between electrically conductive access lines, and the second memory layer in the pair is substantially identical to the first memory layer, but is rotated about an axis perpendicular to the substrate so that the access lines and memory cell rows in one memory layer of the pair are orthogonal to their counterpart lines and rows in the other memory layer. The memory cells in each layer are aligned vertically (perpendicular to the substrate) with the memory cells in the other layer, with the vertically aligned memory cells forming memory cell columns that extend perpendicularly from the substrate. Each memory cell column has an electrical switch between the lowermost memory cell and the substrate.

Abstract: A magnetic random access memory (MRAM) has multiple stacked memory layers, with each memory layer being a plurality of alternating rows of memory cells and electrically conductive access lines. The access lines in each layer are aligned with the access lines in the layers above and below. Similarly the memory cell rows in each layer are aligned with the memory cell rows in the layers above and below, with the memory cells in adjacent layers forming memory cell columns that extending perpendicularly from the MRAM substrate. The memory cells are connected to bit and word lines for addressing selected cells. The MRAM includes electrical circuitry connected to the access lines for directing currents through the access lines in the memory layer of the selected cell and in the access lines directly above or below to generate magnetic fields that switch the magnetic state of the selected cell without switching the magnetic state of non-selected cells in the memory layers above and below.

Abstract: A “toggling” type of magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate with each memory stack having a plurality of toggle memory cells stacked along the Z axis. Each memory stack is located at an intersection region between two orthogonal write lines. Each cell in the stack is a “toggle” cell that has its synthetic antiferromagnet (SAF) free layer easy axis of magnetization aligned nonparallel with the X and Y axes and angularly spaced about the Z axis from the easy axes of magnetization of all the other SAF free layers in the stack. Each cell in a stack is magnetically separated from adjacent cells in the stack by a nonmagnetic separation layer. The magnetization direction of the free layer in a selected memory cell in a stack can be switched without switching the magnetization directions of the free layers in the other memory cells in the stack.

Abstract: A “toggling” type of magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate with each memory stack having a plurality of toggle memory cells stacked along the Z axis. Each memory stack is located at an intersection region between two orthogonal write lines. Each cell in the stack is a “toggle” cell that has its synthetic antiferromagnet (SAF) free layer easy axis of magnetization aligned nonparallel with the X and Y axes and angularly spaced about the Z axis from the easy axes of magnetization of all the other SAF free layers in the stack. Each cell in a stack is magnetically separated from adjacent cells in the stack by a nonmagnetic separation layer. The magnetization direction of the free layer in a selected memory cell in a stack can be switched without switching the magnetization directions of the free layers in the other memory cells in the stack.

Abstract: The invention comprises a magnetic random access memory (MRAM) with stackable architecture. A first word line is configured to carry electric current. A first memory column is electrically coupled to the word line and is comprised of a plurality of memory cells electrically coupled and adjacent to each other. Each memory cell is configured to store data by magnetic alignment of the memory cell. A first bit line column is electrically isolated from the first word line and is magnetically coupled to and electrically isolated from the first memory column. The first bit line column comprises a plurality of bit lines that are electrically isolated from each other and configured to carry electric current during a memory read and a memory write. The first bit line column is parallel to the first memory column.