Magnetic memory device
View Patent ↗A width and a thickness of a bit line are represented as W 1 and T 1 , respectively, a thickness of a digit line is represented as T 2 , and a distance from a center of the digit line in a thickness direction to a center of a free layer of an MTJ element in the thickness direction is represented as L 1 . A width of the digit line is represented as W 2 , and a distance from a center of the bit line in the thickness direction to the center of the free layer of the MTJ element in the thickness direction is represented as L 2 . The distances L 1 and L 2 and the cross-sectional areas S 1 and S 2 are set in such a manner that when L 1 /L 2 ≧1, a relation of (⅓)·(L 1 /L 2 )≦S 2 /S 1 ≦1 is satisfied and when L 1 /L 2 ≦1, a relation of 1≦S 2 /S 1 ≦3(L 1 /L 2 ) is satisfied.
1. A magnetic memory device comprising:
first and second write wires that intersect each other in a non-contact manner; and
a magnetic tunnel junction element which is arranged in an intersection of said first and second write wires and includes a magnetic tunnel junction, wherein
said magnetic tunnel junction element has a free layer consisting of a ferromagnetic material in which a magnetization direction is variable with a magnetic field generated by current flowing through said first and second write wires, and
in the case where a distance between a center of said first write wire in a thickness direction and a center of said free layer in the thickness direction is represented as L 1 ,
a distance between a center of said second write wire in the thickness direction and a center of said free layer in the thickness direction is represented as L 2 ,
a cross-sectional area of said first write wire in a width direction is represented as S 2 and
a cross-sectional area of said second write wire in a width direction is referred to as S 1 ,
said distance L 1 , said distance L 2 , said cross-sectional area S 1 , and said cross-sectional area S 2 are set in such a manner that
when a ratio of said distance L 1 to said distance L 2 is L 1 /L 2 ≧1,
a relation of (⅓)·(L 1 /L 2 )≦S 2 /S 1 ≦1 is satisfied and
when the ratio of said distance L 1 to said distance L 2 is L 1 /L 2 ≦1,
a relation of 1≦S 2 /S 1 ≦3(L 1 /L 2 ) is satisfied.
2. The magnetic memory device according to claim 1 , wherein
when a relation between said distance L 1 and said distant L 2 is L 1 >L 2 ,
said second write wire is made of a metal material having higher melting point than a melting point of a material for said first write wire, and
when the relation between said distance L 1 and said distant L 2 is L 1 <L 2 ,
said first write wire is made of a metal material having higher melting point than a melting point of a material for said second write wire.
3. The magnetic memory device according to claim 1 , wherein
when a relation between said cross-sectional area S 1 and said cross-sectional area S 2 is S 1 >S 2 ,
said first write wire is made of a metal material having higher melting point than a melting point of a material for said second write wire, and
when the relation between said cross-sectional area S 1 and said cross-sectional area S 2 is S 1 <S 2 ,
said second write wire is made of a metal material having higher melting point than a melting point of a material for said first write wire.