Magnetoresistive element and manufacturing method therefor

摘要

PCT No. PCT/JP92/01581 Sec. 371 Date Jul. 30, 1993 Sec. 102(e) Date Jul. 30, 1993 PCT Filed Dec. 3, 1992 PCT Pub. No. WO93/11569 PCT Pub. Date Jun. 10, 1993.This invention relates to a magnetoresistive element used for a magnetic sensor, etc. A ferromagnetic magnetoresistive element thin film is formed so as to be electrically connected to and so as to overlap the upper end portion of an aluminum wiring metal on a substrate. Through using a vacuum heat treatment with a temperature between 350 DEG and 450 DEG C., a Ni-Al-based alloy is formed at the overlapping portion. Therefore, even when a surface protection film of silicon nitride is subsequently formed by plasma CVD on the substrate, the alloy prevents the nitriding of the upper end portion of the aluminum wiring metal. Accordingly, the surface can be protected from moisture by the silicon nitride film without increasing the contact resistance between the magnetoresistive element thin film and the wiring metal. Instead of the Ni-Al-based alloy, other conductive metals such as TiW, TiN, Ti, Zr, or the like may be used. Also, the surface protection film may be a multi-layered film having a first film containing no nitrogen, such as a silicon oxide film, and a second film of silicon nitride film formed on the first film.