Magnetoresistive device and barrier formation process

Abstract

A magnetoresistive (MR) device and barrier formation process is disclosed in which a barrier layer of an aluminum-titanium oxidic compound of approximately 35 .ANG. thickness is formed between a first alumina film and an overlying material of iron bearing content, such as nickel-iron. The aluminum-titanium oxidic compound layer serves as an etchant barrier for the alumina film in a subsequent etching process to reduce or eliminate "rosette" formation otherwise occurring when etchant is trapped within pores of a porous substrate such as ferrite, ceramic or other polycrystalline material. The barrier layer also serves as a passivation layer to prevent the surface of the underlying alumina film from being modified by the transfer of ultrasonic energy during subsequent wirebonding processing which would otherwise result in film delamination at the nickel-iron/alumina layer interface.

Dependencies are inferred from the claim text.