Phillip Glenn Mather - Maricopa AZ,
Jijun Sun - Chandler AZ,
Young Sir Chung - Chandler AZ,
FREESCALE SEMICONDUCTOR, INC. - Austin TX
A two-axis, single-chip external magnetic field sensor incorporates tunneling magneto-resistance (TMR) technology. In one embodiment, an integrated device includes at least two sensor elements having pinned layers with orientation situated at a known angle (e.g., 90 degrees) with respect to each other. In the presence of a magnetic field, the information from the multiple sensor elements can be processed (e.g., using a conventional bridge configuration) to determine the orientation of the integrated sensor with respect to the external field. In order to achieve an integrated sensor with multiple pinned layer orientations, a novel processing method utilizes antiferromagnetic pinning layers different materials with different blocking temperatures (e.g., PtMn and IrMn).