CN-116381579-B - Planar Hall sensor based on magnetic film on periodic corrugated substrate

CN116381579BCN 116381579 BCN116381579 BCN 116381579BCN-116381579-B

Abstract

The invention discloses a planar Hall sensor based on a magnetic film on a periodic corrugated substrate, which belongs to the technical field of magnetic devices and comprises a periodic corrugated substrate, a buffer layer, a magnetic film layer, a protective layer and a conductive metal layer from bottom to top in sequence, wherein the conductive metal layer comprises two detection planar Hall signal conductive metal layers arranged along a direction perpendicular to the corrugated direction and two external current conductive metal layers arranged along a direction parallel to the corrugated direction. Compared with the traditional planar Hall sensor with shape-induced uniaxial magnetic anisotropy, the planar Hall sensor has the advantages that the technical requirements of precise etching and the like are not needed, the preparation process is more convenient and fast only by adjusting the ripple period and the ripple amplitude of the periodic ripple substrate, the manufacturing cost is lower, and the performance of the planar Hall sensor is easier to regulate and control.

Inventors

ZHONG ZHIYONG
HUANG HAOYANG
XU XU
JIN LICHUAN
TANG XIAOLI
ZHANG HUAIWU

Assignees

电子科技大学

Dates

Publication Date: 20260505
Application Date: 20230315

Claims (4)

1. The planar Hall sensor based on the magnetic film on the periodic corrugated substrate is characterized by comprising the periodic corrugated substrate (1), a buffer layer (2), a magnetic film layer (3), a protective layer (4) and a conductive metal layer which are sequentially arranged from bottom to top, wherein the conductive metal layer comprises two detection planar Hall signal conductive metal layers (5) which are arranged along the direction perpendicular to the corrugated direction and two external current conductive metal layers (6) which are arranged along the direction parallel to the corrugated direction; The ripple period of the periodic ripple substrate (1) is 10 nm-1 mu m, and the ripple amplitude is 10 nm-100 nm; The magnetic film with the periodic ripple structure is obtained by depositing the magnetic film layer (3) on the periodic ripple substrate (1), the patterning magnetic film is used for inducing uniaxial anisotropy, and the patterning magnetic film can be obtained by adjusting the ripple period and the ripple amplitude of the periodic ripple substrate (1).
2. The planar hall sensor based on the magnetic thin film on the periodic corrugated substrate according to claim 1, wherein the periodic corrugated substrate (1) is a sapphire substrate, and is obtained by annealing the planar sapphire substrate at 1100-1400 ℃ for 2-10 h.
3. The planar hall sensor based on the magnetic film on the periodic corrugated substrate according to claim 1, wherein the magnetic film layer (3) is a NiFe film, a NiCo film or a FeCo film, and is prepared by adopting an evaporation coating, a sputtering coating or a molecular beam epitaxy process, and has a thickness of 10 nm-300 nm.
4. The planar hall sensor based on the magnetic thin film on the periodic corrugated substrate according to claim 1, wherein the materials of the buffer layer (2) and the protective layer (4) are Ta, the planar hall sensor is prepared by adopting an evaporation coating process, a sputtering coating process or a molecular beam epitaxy process, the thickness of the buffer layer (2) is 2 nm-10 nm, and the thickness of the protective layer (4) is 1 nm-5 nm.

Description

Planar Hall sensor based on magnetic film on periodic corrugated substrate Technical Field The invention belongs to the technical field of magnetic devices, and particularly relates to a planar Hall sensor based on a magnetic film on a periodic corrugated substrate. Background Along with the rapid development of modern information technology, the magnetoresistive sensor is widely applied to various fields such as biosensors, industrial detection, aerospace, positioning and navigation, and is developed towards miniaturization and high sensitivity. The main principle of the magnetoresistive sensor is the magnetoresistive effect (MR), which mainly comprises an anisotropic magnetoresistive effect (AMR) sensor, a Planar Hall Effect (PHE), a giant magnetoresistive effect (GMR) sensor, a tunneling magnetoresistive effect (TMR) sensor, and the like. The planar Hall sensor has the advantages of high detection precision, low noise, low thermal drift and the like, can be used for detecting magnetization offset under a micro magnetic field, and can also be used for measuring micro magnetic beads under a micro-nano scale, so that the planar Hall sensor has wide application prospect in the aspect of biological sensors. Planar hall sensors are very sensitive to disturbances that capture the magnetization direction of the ferromagnetic layer, and require a good control of the magnetization direction of the sensor in the zero-field state, which requires that the ferromagnetic layer of the sensor have uniaxial anisotropy. The current mainstream preparation method mainly induces uniaxial anisotropy by changing the shape of the magnetic film, such as elliptic type plane Hall sensor, cross-junction type plane Hall sensor and the like. Since the uniaxial anisotropic field of the magnetic film has a large influence on the sensor performance, the precise etching of patterns on the manufacturing process is highly required. How to induce the uniaxial anisotropy of the magnetic film by other modes so as to reduce the manufacturing cost of the planar Hall sensor and regulate the size of an anisotropy field to obtain the planar Hall sensor with specified performance is a problem which needs to be solved urgently before the planar Hall sensor is pushed to the practical application process. Disclosure of Invention The present invention aims to solve the above-mentioned problems in the prior art, and provides a planar hall sensor based on a magnetic thin film on a periodic corrugated substrate, which induces uniaxial anisotropy by a patterned magnetic thin film without precise etching. The technical scheme adopted by the invention is as follows: The planar Hall sensor based on the magnetic film on the periodic corrugated substrate is characterized by comprising a periodic corrugated substrate 1, a buffer layer 2, a magnetic film layer 3, a protective layer 4 and a conductive metal layer which are sequentially arranged from bottom to top, wherein the conductive metal layer comprises two detection plane Hall signal conductive metal layers 5 which are arranged along the direction perpendicular to the corrugated direction, and two external current conductive metal layers 6 which are arranged along the direction parallel to the corrugated direction. Further, the periodic corrugated substrate 1 is a sapphire substrate, and is obtained by annealing a planar sapphire substrate at 1100-1400 ℃ for 2-10 hours. Further, the ripple period of the periodic ripple substrate 1 is 10 nm-1 μm, and the ripple amplitude is 10 nm-100 nm. Further, by adjusting the annealing temperature and the annealing time length, the ripple period and the ripple amplitude of the periodic ripple substrate 1 are changed, so that the size of the anisotropic field of the magnetic thin film layer 3 is regulated, and the performance regulation of the planar Hall sensor is realized. Further, a buffer layer 2, a magnetic thin film layer 3, and a protective layer 4 are sequentially obtained on the periodic corrugated substrate 1 using a thin film deposition process. Further, the magnetic thin film layer 3 may be made of a NiFe thin film, a NiCo thin film, a FeCo thin film, or the like, and is prepared by thin film deposition techniques such as evaporation coating, sputter coating, molecular beam epitaxy, or the like, and has a thickness of 10nm to 300nm. Further, the materials of the buffer layer 2 and the protective layer 4 are Ta, and the buffer layer 2 is prepared by adopting thin film deposition processes such as evaporation coating, sputtering coating, molecular beam epitaxy and the like, the thickness of the buffer layer 2 is 2 nm-10 nm, and the thickness of the protective layer 4 is 1 nm-5 nm. Further, the conductive metal layer is made of conductive metals such as copper and gold, and the thickness of the conductive metal layer is 50 nm-100 nm. Further, by applying a current to the two external current conducting metal layers 6 arranged in parallel to the ripple direction, th