Single-chip magnetic sensor, and laser heating-assisted annealing apparatus thereof and laser heating-assisted annealing method thereof

Abstract

The invention discloses a single-chip magnetic sensor, and a laser heating-assisted annealing apparatus thereof and a laser heating-assisted annealing method thereof. The laser heating-assisted annealing method comprises the following steps: (a), annealing is carried out on a magnetic thin film in a strong magnetic field, so that magnetic moments on a pinning layer of the magnetic thin film are towards a same direction; (b), the magnetic thin film is fixedly disposed on a clamp of a movable platform; (c), a laser source is opened to emit a laser beam, which is attenuated through an optical attenuator; the direction of the attenuated laser beam is changed through a reflective mirror; and the laser beam with the changed direction is focused into a light spot by a focusing objective lens; (d), the movable platform is moved, in order that the focused light spot of the laser beam is aimed at the magnetic thin film so as to enable the magnetic thin film to be heated by the laser beam; (e), a magnetic field intensity of an electromagnet arranged on the movable platform is adjusted, so that a magnetic domain of the heating area of the magnetic thin film can be overturned; and (f), the magnetic thin film is cut into slices, and the slices of the cut magnetic thin film are bound into one.

Description

technical field [0001] The invention relates to the field of GMR and MTJ (Magnetic Tunnel Junction) spin valve magnetoresistive sensors, in particular to a single-chip magnetic sensor and its laser heating assisted annealing device and method, which can assist GMR and MTJ to achieve The local reversal of the magnetic moment of the pinning layer, the method can be used to make half-bridge, full-bridge, biaxial half-bridge, biaxial full-bridge GMR, MTJ magnetic sensor on the magnetic thin film. Background technique [0002] Magnetic Tunnel Junction sensor (MTJ, Magnetic Tunel Junction) is a new type of magnetoresistance effect sensor that has been applied in industry in recent years. With the change of the magnitude and direction of the external magnetic field in the material, the resistance of the magnetic multilayer film changes significantly. It has a greater resistance change rate than the previously discovered and practically applied AMR (anisotropic magnetoresistance eff...

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Problems solved by technology

Therefore, when preparing GMR and MTJ full bridges on a single silicon wafer, it cannot be achieved by annealing the GMR and MTJ silicon wafers in the same strong magnetic field.

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