Process integration of a single chip three axis magnetic field sensor

Abstract

A semiconductor process integrates three bridge circuits, each include magnetoresistive sensors coupled as a Wheatstone bridge on a single chip to sense a magnetic field in three orthogonal directions. The process includes various deposition and etch steps forming the magnetoresistive sensors and a plurality of flux guides on one of the three bridge circuits for transferring a ''Z'' axis magnetic field onto sensors orientated in the XY plane.

Description

technical field [0001] The present invention relates generally to the field of magnetoelectronic devices, and more particularly to the process of integrating CMOS compatible magnetoelectronic magnetic field sensors for sensing magnetic fields along three orthogonal directions on a single chip. Background technique [0002] Sensors are widely used in modern systems to measure or detect physical parameters such as position, motion, force, acceleration, temperature, pressure, etc. While many different sensor types exist for measuring these and other parameters, they all suffer from various limitations. For example, inexpensive low-field sensors such as those used in electronic compasses and other similar magnetic sensing applications often include anisotropic magnetoresistance (AMR) based devices. In order to obtain the required sensitivity and appropriate resistance well matched with CMOS, the size of the sensing unit of this sensor is generally on the order of square millime...

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Problems solved by technology

Since the size of vertically bonded chips is generally dictated by the pad pitch determined by handling constraints, this technique results in a large vertical s

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