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US 7,120,048 B2Granted
Nonvolatile memory vertical ring bit and write-read structure
AssigneeHoneywell International Inc.
InventorLance Sundstrom
Life of this patent
Estimating the term…
Abstract
A magnetoresistive memory cell and array are provided for nonvolatile storage of binary information. According to an embodiment, a memory cell has a ring-shaped magnetoresistive multilayer element (or bit). A plurality of vias pass through a center hole in the ring-shaped element. Each end of each via is coupled with a separate write-read line segment that extends radially from the center hole past a perimeter of the ring-shaped element. The write-read lines are configured to generate magnetic fields for switching a magnetization direction of one or more layers of the ring-shaped bits in the array.
Claims27
A magnetoresistive (MR) memory cell comprising:
- a ring-shaped magnetoresistive multilayer element having a base, a top, a hole passing through the center of the element, and a curved surface at the perimeter of the element wherein the ring-shaped magnetoresistive multilayer element comprises a nonmagnetic conducting ring layer sandwiched between a first ferromagnetic layer and a second ferromagnetic layer, and wherein the coercivity of the first layer is greater than the coercivity of the second layer;
- and
- at least one write-read line, each write-read line comprising:
- a via passing through the hole, wherein the via is electrically isolated from the element;
- a top write-read line segment arranged near the top and coupled with the via, wherein the top word line extends radially from the via toward the perimeter and wherein the top write-read line is electrically isolated from the element;
- and
- a base write-read line segment arranged near the base and coupled with the via, wherein the base write-read line extends radially from the via toward the perimeter and wherein the base write-read line is electrically isolated from the element,
- whereby each write-read line is configured such that a current passing through the write-read line creates a magnetic field for switching a magnetic direction of a layer of the element.
5 more elements
A magnetoresistive memory array comprising:
- a plurality of ring-shaped multilayer magnetoresistive elements arranged in rows and columns, each element having an inner circumference, an outer circumference, a top edge, and a bottom edge, wherein the inner circumference defines a center hole of the element;
- a plurality of row write-read lines, wherein each row write-read line has an associated row, each row write-read line comprising:
- a first half of the row write-read line passing from a first side of the associated row to a second side of the associated row, wherein the first half of the row write-read line passes through the center hole of each element in the associated row;
- a second half of the row write-read line passing from the second side of the associated row to the first side of the associated row, wherein the second half of the row write-read line passes through the center hole of each element in the associated row;
- and
- a loop for interconnecting the first half of the row write-read line with the second half of the row write-read line at the second side of the row;
- a plurality of column write-read lines, wherein each column has an associated column write-read line, each column write-read line comprising:
- a first half of the column write-read line passing from a first side of the associated column to a second side of the associated column, wherein the first half of the column write-read line passes through the center hole of each element in the associated column;
- a second half of the column write-read line passing from the second side of the associated column to the first side of the associated column, wherein the second half of the column write-read line passes through the center hole of each element in the associated column;
- and
- a loop for interconnecting the first half of the column write-read line with the second half of the column write-read line at the second side of the column.
8 more elements
A magnetoresistive memory cell comprising:
- a ring-shaped magnetoresistive multilayer element having a base, a top, a hole passing through the center of the element, and a curved surface at the perimeter of the element;
- four vias arranged within the hole, wherein each via extends from the base to the top and is electrically isolated from the element and from the other vias;
- a first x-axis top trace arranged near the top and coupled with a first via of the four vias;
- a first x-axis base trace arranged near the base and coupled with the first via;
- a second x-axis top trace arranged near the top and coupled with a second via of the four vias;
- a second x-axis base trace arranged near the base and coupled with the second via;
- a first y-axis top trace arranged near the top and coupled with a third via of the four vias;
- a first y-axis base trace arranged near the base and coupled with the third via;
- a second y-axis top trace arranged near the top and coupled with a fourth via of the four vias;
- a second y-axis base trace arranged near the base and coupled with the fourth via,
- wherein each trace extends radially from the hole past the perimeter.
8 more elements
Dependencies are inferred from the claim text.