Magnetic tunnel junction structures having bended tips at both ends thereof, magnetic random access memory cells employing the same and photomasks used in formation thereof

A magnetic random access memory (MRAM) cell, comprising:

• an access transistor formed on an integrated circuit substrate;
• a digit line disposed over the substrate;
• a bottom electrode disposed over the digit line and electrically connected to an output terminal of the access transistor;
• a magnetic tunnel junction structure including a pinned layer pattern, a tunneling insulation layer pattern and a free layer pattern, which are stacked on the bottom electrode, at least the free layer pattern including a rectangular main body as well as first and second tips that protrude from both ends of the main body, respectively, the main body having first and second sides that face each other, the first side of the main body being along an outer surface of at least the free layer pattern, a third side extended from one end of the first side to contact one end of the second side and a fourth side extended from the other end of the first side to contact the other end of the second side, the first tip protruding from a first vertex corresponding to a contact point of the second and third sides, an outer surface of the first tip contacting the second and third sides, and the first tip being bent to have a configuration of a rounded curve, wherein the first vertex is on a same side of the first tip as a center of curvature of the rounded curve of the first tip, and the second tip protruding from a second vertex corresponding to a contact point of the second and fourth sides, an outer surface of the second tip contacting the second and fourth sides, and the second tip being bent to have a configuration of a rounded curve, wherein the second vertex is on a same side of the second tip as a center of curvature of the rounded curve of the second tip, and wherein the first and second tips expose the first and second sides;
• a top electrode disposed on the magnetic tunnel junction structure;
• and
• a bit line disposed over the top electrode and electrically connected to the top electrode.