Mini-acoustical device based on magneto resistor effect

Abstract

The invention discloses a tiny acoustics device, which is based on magnetoelectric effect. The invention belongs to semiconductor device field. The device is composed by movable diaphragm structure which has aggradation of hard magnetism film, and immovable structure which has aggradation of magnetic resistor several layers films. The movable diaphragm structure is composed from bottom to top by silicon underlay, silicon dioxide, silicon nitride layer, permanent magnetic material layer and silicon dioxide layer, the structure of immovable is same to the movable part, besides changing the permanent magnetic material layer to GMR magnetic resistor several layers film. The invention achieves diversion of electronic signal and acoustic signal between movable diaphragm film and magnetic resistor several layers films, so the tiny acoustics device which has high sensitivity, low yawp, wide range of response, and the following dealing circuit is very simple, because the technologic step is simple, the character of product is reliable, the rate of finished products is high, and is suitable to requirement of volume-produce.

Description

technical field [0001] The invention belongs to the field of semiconductor devices, in particular to a micro-acoustic device based on the magnetoresistance effect. Background technique [0002] The MR (magnetoresistance) effect refers to the phenomenon that the resistance of a substance changes under the action of a magnetic field. As early as 1857, the anisotropic magnetoresistance (AMR) effect of ferromagnetic polycrystals was discovered, but its application in the field of sensors was limited due to its low sensitivity. After 1988, the discovery of giant magnetoresistance effect (GMR), tunnel magnetoresistance effect (TMR) and colossal magnetoresistance effect (CMR) in metal multilayer films activated this field. Magnetoresistance materials can be made into various high-sensitivity magnetic sensors to detect weak magnetic field signals. Compared with various traditional sensors, the advantages of MR sensors are very prominent: small size, high sensitivity, low impedance...

AI Technical Summary

Problems solved by technology

Chinese Invention Patent (Application No.: 01140441.8) proposes the design and manufacturing process of a textured film condenser silicon-based microphone. The textured film structure is used to reduce the influence of the residual stress in the film on the performance of the microphone, and it is expected to obtain better device performance. , but its preparation process is very complicated, requiring the combination of bulk silicon process and sacrificial layer process, and the reliability and yield are greatly limited

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