High Sensitivity TMR Magnetic Sensor

A method of fabricating a TMR sensor device comprising a first TMR resistor, a second TMR resistor, a third TMR resistor, and a fourth TMR resistor, comprising:

• forming a first bottom lead and a second bottom lead in a first dielectric layer;
• depositing a first TMR film over the first and second bottom leads and the first dielectric layer;
• forming the first TMR resistor and the fourth TMR resistor from the first TMR film by removing one or more first portions of the first TMR film disposed over the first dielectric layer;
• forming a plurality of middle leads;
• depositing a second TMR film over the plurality of middle leads, the second TMR film being different than the first TMR film;
• forming the second TMR resistor and the third TMR resistor from the second TMR film by removing one or more first portions of the second TMR film disposed over the first and second TMR resistors;
• and
• forming a plurality of top leads.

A method of fabricating a TMR sensor device, comprising:

• forming a first bottom lead and a second bottom lead;
• depositing a first TMR film over the first and second bottom leads, the first TMR film comprising a synthetic anti-ferromagnetic pinned layer having a magnetization direction of a first reference layer orthogonal to a magnetization direction of a first free layer;
• depositing a first photoresist over first portions of the first TMR film disposed on the first bottom lead and the second bottom lead;
• etching second portions of the first TMR film to expose a first dielectric layer;
• removing the first photoresist;
• forming a first middle lead over the first TMR film and the first bottom lead, a second middle lead on the first dielectric layer adjacent to the first middle lead, a third middle lead on the first dielectric layer adjacent to the first middle lead, and a fourth middle lead over the first TMR film and the second bottom lead;
• depositing a second TMR film over the first, second, third, and fourth middle leads, the second TMR film comprising a double synthetic anti-ferromagnetic pinned layer having a magnetization direction of a second reference layer orthogonal to magnetization direction of a second free layer and opposite to the magnetization direction of the first reference layer of the first TMR film;
• depositing a second photoresist over first portions of the second TMR film disposed over the second and third middle leads;
• etching second portions of the second TMR film to expose the first and fourth middle leads;
• removing the second photoresist;
• and
• forming a first top lead over the first middle lead, a second top lead over the second TMR film and the second middle lead, a third top lead over the second TMR film and the third middle lead, and a fourth top lead over the fourth middle lead.