Thin-film magnetoresistive sensor element and thin-film magnetoresistive bridge

Abstract

The invention relates to a thin-film magnetoresistive sensor element. The thin-film magnetoresistive sensor element comprises a lower electrode, a seed layer, an anti-ferromagnetic pinning layer, magnetic nail-pinning layer structure, a non-magnetic isolation layer, a magnetic free layer, a protecting layer, an upper electrode and a magnetic biasing layer. The invention also relates to a bridge for the thin-film magnetoresistive sensor. The thin-film magnetoresistive sensor element and the bridge thereof disclosed by the invention have the characteristics of small magnetic retardation, high precision and linearity, adjustable linear range, simple process, high response frequency, low cost, strong anti-jamming property and favorable temperature characteristic.

Description

technical field [0001] The invention relates to a thin-film magnetoresistance sensor and a half-bridge and a full-bridge composed of the thin-film magnetoresistance. Background technique [0002] Thin film magnetoresistive sensor elements are widely used in data storage (computer hard disk, MRAM), current measurement, position measurement, object movement and speed, angle and angular velocity measurement. [0003] The thin film magnetoresistive sensor element has a multilayer film structure and a spin valve structure. A multilayer film structure includes magnetic and nonmagnetic layers, which are alternately deposited on a substrate. The spin valve structure includes nonmagnetic pinning layer (MnIr, MnPt), magnetic pinned layer (CoFeB, CoFe, or SAF structure CoFe / Ru / CoFe, etc.), nonmagnetic isolation layer (Cu, AlO, MgO, HfO , ZrO, TaO, etc.), magnetic free layer (CoFeB, CoFe, or SAF structure CoFe / Ru / CoFe, etc.). [0004] When the thin film magnetoresistive sensor elemen...

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Problems solved by technology

[0005] The characteristics of the first method are: the process is simple, but the bias magnetic field provided by the shape anisotropy is limited, and it limits the design of the chip

The characteristic of adopting the second method is: the size of the bias magnetic field can be changed by adjusting the composition and thickness of the permanent magnetic film, but in practical applications, it is necessary to avoid the interference of a large external magnetic field. If there is interference of a large magnetic field, the bias will be changed. The direction of the magnetic field, which affects the performance of the sensor

The characteristic of the third method is that the size of the bias magnetic field can be adjusted by changing the size of the current, but the power consumption of the sensor will be large

The characteristics of adopting the fourth method are: the size of the bias magnetic field can be changed by adjusting the thickness of the antiferromagnetic material and the thickness or material of the free layer, but in practical applications, the thermal stability of this structure is poor, and the current materials Difficult to stabilize the performance of the sensor above 200 degrees Celsius

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