Preparation method of quasi isotropic magnetic core film

Abstract

The invention provides a preparation method of a quasi isotropic magnetic core film, and relates to the field of preparation of magnetic thin films in high-frequency magnetic devices, especially on-chip integrated inductors. According to the preparation method, a substrate inclines, the substrate and target materials are sputtered at a certain angle to form an inclined columnar structure, and a uniaxial anisotropy field is introduced. In a magnetic thin film / insulating layer / magnetic thin film sandwich structure, the upper and lower layers of magnetic thin films are of an inclined columnar structure with opposite easy-axis directions to generate an appropriate interlayer exchange coupling effect and to offset a shape anisotropy field caused by different length-width ratios, so that the total effective anisotropy field only depends on an inclined sputtering-induced anisotropy field. The magnetic core film is formed by stacking a plurality of sandwich structures, easy axes of the magnetic thin films in adjacent sandwich structures are vertical to one another, and the interlayer exchange coupling effect is isolated through isolating layers which are greater than 20nm in thickness, so that the magnetic core film has similar effective anisotropy fields and relatively high magnetic conductivity in various directions.

Description

technical field [0001] The invention relates to the field of preparation of magnetic thin films in high-frequency magnetic devices, especially on-chip integrated inductance devices, in particular to a preparation method of a quasi-isotropic magnetic core film independent of shape anisotropy fields. Background technique [0002] With the rapid development and application of portable and wearable devices, higher requirements are put forward for the integration, high frequency and low power consumption of electronic components. At present, magnetic devices, which are an important part of electronic components, have been lagging behind the development of other devices due to various reasons. One of the main reasons is that the magnetic properties, high-frequency characteristics and bulk materials exist after the thin film and miniaturization of magnetic materials. Very big difference. How to utilize or eliminate the shape anisotropy field (or demagnetization field) introduced a...

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Problems solved by technology

[0003] On the other hand, due to the existence of uniaxial anisotropy, taking inductance as an example, when the magnetic field component of the electromagnetic wave is parallel to the difficult axis of the film, the gain of the inductance is close to the effective permeability, but when the magnetic field component of the electromagnetic wave is parallel to the film When the easy axis of the film is parallel, since the relative permeability of the easy axis of the film is close to 1, it means that the magnetic material has no gain to the inductance at this time

However, in the design of actual inductors, whether it is a spiral, solenoid type, or racetrack type on-chip inductor, it is difficult to make the anisotropy required by all magnetic cores in the same direction, which makes the film in each direction Both need to have a large magnetic permeability and "quasi-isotropy", that is, it is hoped that the magnetic core film has the same or similar effective anisotropy field in any in-plane direction

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