Preparing method of triaxial anisotropic magnetoresistor

Abstract

The invention provides a preparing method of a triaxial anisotropic magnetoresistor. The preparing method includes: in first etching, etching only magnetic material on the bottom surface of a trench; in second etching, etching the magnetic material on the surface of a substrate to form planar magnetic resistance and vertical resistance spaced, thereby forming the triaxial anisotropic magnetoresistor. The bottom surface of the trench and the surface of the substrate are never etched at the same time, and thus, the surface of the substrate being over-etched due to difference of etching rates is avoided. Therefore, separate etching of the magnetic material on the trench and that on the surface of the substrate leads to no over-etching and ensures performance of the triaxial anisotropic magnetoresistor.

Description

technical field [0001] The invention relates to the field of semiconductor design and manufacture, and more specifically, the invention relates to a preparation method of 3-axis anisotropic magnetoresistance. Background technique [0002] Anisotropic magnetoresistive (AMR) sensor is a new type of magnetoresistance effect sensor in modern industry, AMR sensor is becoming more and more important, especially in the latest smartphones, as well as parking sensors, angle sensors, automatic braking in the automotive industry System (ABS) sensors and tire pressure sensors are widely used. In addition to the anisotropic magnetoresistive (AMR) sensor, the current main technical branches of magnetic sensors include Hall sensor, giant magnetic sensor (GMR), tunnel junction magnetic sensor (TMR), etc. The sensitivity of the sensor is much higher, and the technology is more mature than GMR and TMR, so the application of anisotropic magnetoresistive (AMR) sensor is more extensive than tha...

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Problems solved by technology

[0006] Please refer to Figure 4 , Figure 4 for image 3 The partially enlarged view of the dotted line box, when the first etching is performed, because the trench 10 is very deep, the rates of simultaneously etching the magnetoresistive material 20 at the bottom of the trench 10 and the magnetoresistive material 20 on the substrate surface are different, Cause over etching (Over etch) on the surface of the substrate, when the second etching forms the spacing, because the etching will appear to align the overlapping region (Overlap) 30, cause the second etching will affect the surrounding area of ​​the planar magnetism 22. Align the overlapping area 30 to etch again, so that the over-etching of the substrate surface is deteriorated

thus affecting the performance of the resulting 3-axis AMR

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