3-axis magnetic field sensor, method for fabricating magnetic field sensing structure and magnetic field sensing circuit

A 3-axis magnetic field sensor, comprising:

• a first in-plane magnetic field sensor, located on a substrate to sense an X-axis magnetic field, and having a first tunneling magneto-resistor (TMR) and a first easy-axis, wherein the first easy-axis is regarded as a Y-axis;
• a second in-plane magnetic field sensor, located on the substrate to sense a Y-axis magnetic field, and having a second TMR and a second easy-axis, wherein the second easy-axis is regarded as an X-axis,
• an included angle between the first easy-axis and the second easy-axis is 90±10 degrees, and a bisection direction on the substrate respectively include an angle of 45±5 degrees with the first easy-axis and the second easy-axis;
• an out-of-plane magnetic field sensor, located on the substrate to sense a Z-axis magnetic field, and the out-of-plane magnetic field sensor comprising:
• a groove or bulge structure, located on the substrate, and having a first incline, a second incline and a central axis, wherein the first incline and the second incline have a same bevel angle relative to the substrate and are symmetric relative to the central axis, and the central axis is orthogonal to the bisection direction;
• a third TMR, formed on the first incline, and having a third easy-axis;
• a fourth TMR, formed on the second incline, and having a fourth easy-axis,
• wherein the third easy-axis and the fourth easy-axis are parallel to the central axis;
• and
• a tunneling magneto-resistance reference unit, located on the substrate, and having a fifth TMR and a fifth easy-axis, wherein the fifth easy-axis is parallel to the bisection direction.