Anisotropic magnetoresistive permalloy buffer layer preparation method

Abstract

The invention discloses an anisotropic magnetoresistive permalloy buffer layer preparation method. The method comprises the steps that a substrate which is thoroughly cleaned is put into a vacuum cavity, argon gas is provided in the whole process, a buffer layer is deposited by adopting the pulse radio frequency as a sputtering power source, then a NiFe layer is deposited, and finally a covering layer is deposited. The pulse radio frequency technology is adopted, power is supplied to a target gun at intervals during thin film deposition, time is provided for migration of material atoms on the surface of the substrate due to pulse radio frequency interval deposition, and the thin film flatness is improved, so that the crystalline degree of the thin film is enhanced, and the material AMR value is increased; by means of the pulse radio frequency deposition technology, the deposition atoms can sufficiently migrate on the surface of the substrate, the surface flatness of the buffer layer is improved, growth of the NiFe thin film structure can be better induced at normal temperature, and the crystalline grain diameter is increased, so that the permalloy thin film AMR value is increased, the coercive force is lowered, and the thin film sensitivity becomes better.

Description

technical field [0001] The invention relates to a method for preparing an anisotropic magnetic resistance permalloy buffer layer, belonging to the technical field of electronic product preparation. Background technique [0002] Permalloy thin film materials (mainly composed of Ni-Fe) with anisotropic magnetoresistance (AMR) effect are widely used in the production of various high-sensitivity magnetic sensors such as computer hard disk read heads, and are widely used in automation technology, household appliances, Navigation systems, mobile communications, mass storage and computers. At the same time, because the anisotropic magnetoresistivity is related to the angle of the magnetic field and the current, this material has a unique application prospect in the fields of geomagnetic navigation. The usual structure of this AMR thin film material is shown in the figure Figure 5 , first deposit a thinner buffer layer on the substrate, such as tantalum Ta, MgO or NiFeCr, then depo...

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Problems solved by technology

[0004] Although the above method is technically mature, for some products that require thin film patterning, it is necessary to use photoresist to photoetch the pattern on the silicon wafer, and then use it to deposit the thin film, which makes it impossible to use a heating substrate. However, the AMR of the film deposited at room temperature is very small, and the coercive force is very large. Even if it is annealed at high temperature afterwards, its performance cannot meet the requirements for use, which makes the use of this film very popular. very restrictive

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