Non-volatile magnetic memory device

Abstract

A non-volatile magnetic memory cell having a magnetic element with multiple segments which are not co-linear. Each of the segments is magnetized with a remnant magnetic field using a single write line. The segments can be magnetized in a first direction or a second direction, corresponding to first and second orientations of the memory cell. A sensor is provided to determine the direction in which the segments are magnetized and thereby the orientation of the cell. The segments are oriented such that the magnetic flux fields created by their respective remnant magnetic fields have a cumulative effect at a sensing region of the sensor. The cumulative effect allows a less sensitive sensor to be used than in known device. In various embodiments, the magnetic element can have a number of linear segments or a curved profile. In another embodiment, multiple magnetic elements are magnetized by a single write line. The multiple magnetic elements are arranged such that remnant magnetic field stored in them can be cumulatively sensed. In another embodiment, the magnetic element is arranged to be magnetized in a single general direction, but is shaped such that magnetic flux lines emanate from it in different directions. The different directions are arranged to direct flux lines through the sensing region of a sensor, which measures their cumulative effect.

1 - 38 . (canceled) 
   
   
       39 . A memory cell comprising:
 (a) a non-linear magnetic element;   (b) a write line for storing a remnant magnetic field in said magnetic element;   (c) a sensor having a sensing region and wherein magnetic flux fields produced by each of said magnetic fields pass through said sensing region   wherein said magnetic element has two or more segments:   said segments are not co-linear;   each of said segment stores a magnetic field;   each of said magnetic flux field passes through a sensing region of the sensor; and   the sensor is a Hall sensor.   
   
   
       40 . The memory cell of  claim 39  wherein the sensor is made of a material that is compliant with a CMOS process. 
   
   
       41 . The memory cell of  claim 39  wherein the sensor is made of a n-type region in said substrate. 
   
   
       42 . The memory cell of  claim 39  wherein the substrate is formed of silicon and wherein the sensor is formed by doping a region of the substrate. 
   
   
       43 . The memory cell of  claim 39  wherein the sensor is made by doping said substrate with phosphorus. 
   
   
       44 . The memory cell of  claim 39  wherein a metal layer is formed between said magnetic element and said sensor. 
   
   
       45 . The memory cell of  claim 44  wherein said sensor and said metal layer form a diode for electrically isolating said magnetic element from said sensor. 
   
   
       46 . The memory cell of  claim 39  wherein the sensor has a current application line and a voltage measurement line and wherein the sensing region is defined by an intersection of said current application line and said voltage measurement line. 
   
   
       47 - 65 . (canceled) 
   
   
       66 . A memory cell comprising:
 (a) a magnetic element having a notched section;   (b) a write line adjacent to said magnetic element for storing a remnant magnetic field in said magnetic element, wherein said magnetic field may have a first orientation or a second orientation; and   (c) a sensor for detecting the orientation of said magnetic field.   
   
   
       67 . The memory cell of  claim 66  wherein said write line is geometrically linear. 
   
   
       68 . The memory cell of  claim 66  wherein said sensor has a sensing region and wherein said notched section is defined by two or more sides of said magnetic element and wherein said sides are adjacent to said sensing region. 
   
   
       69 - 72 . (canceled) 
   
   
       73 . The memory cell of  claim 66  wherein the magnetic element and the sensing region are substantially parallel. 
   
   
       74 . The memory cell of  claim 66  wherein the sensor is a Hall sensor. 
   
   
       75 . The memory cell of  claim 66  wherein the sensor is made of a material that is compliant with a CMOS process. 
   
   
       76 . The memory cell of  claim 66  wherein the sensor is made of a n-type region in said substrate. 
   
   
       77 . The memory cell of  claim 66  wherein the substrate is formed of silicon and wherein the sensor is formed by doping a region of the substrate. 
   
   
       78 . The memory cell of  claim 66  wherein the sensor is made by doping said substrate with phosphorus. 
   
   
       79 . The memory cell of  claim 66  wherein a metal layer is formed between said magnetic element and said sensor. 
   
   
       80 . The memory cell of  claim 79  wherein said sensor and said metal layer form a diode for electrically isolating said magnetic element from said sensor. 
   
   
       81 . The memory cell of  claim 68  wherein the sensor has a current application line and a voltage measurement line and wherein the sensing region is defined by an intersection of said current application line and said voltage measurement line.