High-sensitivity vertical magnetic field sensor with symmetrical structure

Abstract

The invention discloses a high-sensitivity vertical magnetic field sensor with a symmetrical structure. The magnetic field sensor comprises a first vertical magnetic field sensor and a second verticalmagnetic field sensor, which are vertically and symmetrically arranged, wherein the first vertical magnetic field sensor and the second vertical magnetic field sensor share a third N + region. The magnetic field sensor comprises a silicon substrate, an insulator layer, a first P-region, a second P- region, a third P- region, a fourth P- region, a first N + region, a second N + region, a third N +region, a fourth N + region, a fifth N + region, a gate dielectric layer and a gate. The magnetic field sensor with the symmetrical structure has a simple production process, a completely symmetricalstructure and low initial device offset, furthermore, the device offset can be eliminated by using the rotating current technology, and the residual offset is low. The vertical magnetic field sensorhas high magnetic field sensitivity, and can form a two-dimensional magnetic field sensor to realize the detection of a two-dimensional magnetic field parallel to a device plane.

Description

technical field [0001] The invention relates to a high-sensitivity vertical magnetic field sensor with a symmetrical structure, which can be used in the technical field of electromagnetic detection. Background technique [0002] The vertical magnetic field sensor can detect the magnetic field parallel to the surface of the device to form a two-dimensional (2D) and three-dimensional (3D) magnetic field sensor to realize functions such as precise position positioning, small displacement measurement, rotational movement, current detection and angle measurement. In recent years, vertical Hall magnetic field sensors with low-cost silicon-based technology have been widely used in many fields such as automatic control, automobiles, medical equipment, intelligent instruments and meters, and consumer electronics. Traditional silicon-based CMOS vertical Hall devices such as five-hole and six-hole structures, although the device structure is simple, the initial misalignment of the devi...

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Problems solved by technology

However, this method requires additional processing of the magnetic field concentrator, which increases the production cost and is prone to the disadvantage of magnetic field distortion

At present, new anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), giant magnetoresistance (GMI) and other magnetic field elements show high magnetic field sensitivity and good temperature stability, but they cannot be compared with silicon-based processes. Very good compatibility, but still unable to meet the development requirements of low-cost and high-integration magnetic field sensor microsystems

[0004] At present, low-cost two-dimensional and three-dimensional integrated Hall magnetic sensors based on deep submicron standard silicon-based CMOS technology have serious problems of low magnetic field sensitivity and high offset, especially the extremely low magnetic field sensitivity and non-magnetic field sensitivity of traditional vertical Hall devices. The fully symmetrical device structure has become the biggest bottleneck restricting the development and application of low-cost 2D and 3D integrated Hall sensors

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