Magnetic sensor and forming method

A MEMS device, comprising:

• a first substrate having a first protrusion and a second protrusion extending outward from a lateral surface of the first substrate;
• a magnetic film disposed on the first protrusion;
• a second substrate comprising a recess disposed within a front surface of the second substrate at a location vertically aligned with the magnetic film;
• and
• first and second bonding elements disposed on the second protrusion of the first substrate and the front surface of the second substrate, respectively, wherein the first and second bonding elements are configured to bond the first substrate to the second substrate so that a first sensing gap associated with a first MEMS device is disposed between the magnetic film and the recess and a second sensing gap associated with a second MEMS device is disposed between the lateral surface and the front surface of the second substrate.

A method of forming a magnetic sensor, comprising:

• forming a magnetic film on a front surface of a first substrate;
• forming a recess within a front surface of a second substrate at a first location corresponding to the magnetic film;
• bonding the first substrate to the second substrate, forming a first sensing gap between a bottom surface of the recess and the magnetic film;
• wherein forming the magnetic film comprises:
• forming a magnetic material layer over the first substrate using a sputter, Ion-beam, E-beam, or chemical mechanical deposition (CVD) process;
• covering a portion of the magnetic material layer with a masking layer at a position covering the magnetic film;
• and
• removing a portion of the magnetic material layer not covered by the masking layer using a dry etching process.