Spin-valve thin-film magnetic element and method for fabricating the same

A spin-valve thin-film magnetic element comprising:

• a laminate comprising a nonmagnetic underlying layer in contact with a substrate, a free magnetic layer in contact with the underlying layer, a nonmagnetic conductive layer in contact with the free magnetic layer, a pinned magnetic layer in contact with the nonmagnetic conductive layer, and an antiferromagnetic layer in contact with the pinned magnetic layer;
• bias layers formed on both sides in the track-width direction of the laminate;
• and
• electrode layers formed on the bias layers,
• wherein the bias layers are in contact with both sides of the laminate and extend over the peripheral sections of the laminate with ferromagnetic bias underlying layers therebetween, the bias underlying layers comprising Fe or an Fe-Co alloy and having a thickness of 1.6 to 4.3 nm.

A method for fabricating a spin-valve thin-film magnetic element comprising the steps of:

• forming a laminate by depositing, at least, an antiferromagnetic layer, a pinned magnetic layer in contact with the antiferromagnetic layer, a nonmagnetic conductive layer in contact with the pinned magnetic layer, and a free magnetic layer in contact with the nonmagnetic conductive layer in that order on a substrate;
• forming a lift-off resist layer on the laminate;
• removing the region of the laminate which is not covered with the lift-off resist layer by ion milling so that the laminate has a trapezoidal cross-section;
• forming bias underlying layers by a first sputtering process on both inclined sides of the laminate and over the peripheral sections of the laminate while a sputtering target comprising Fe or an Fe-Co alloy is opposed to the substrate at a predetermined angle so that the thickness of the bias underlying layers on the inclined sides of the laminate is equal to or larger than the thickness of the bias underlying layers over the peripheral sections of the laminate;
• forming bias layers on the bias underlying layers by a second sputtering process;
• and
• forming electrode layers on the bias layers by a third sputtering process.

A method for fabricating a spin-valve thin-film magnetic element comprising the steps of:

• forming a laminate depositing, at least, a free magnetic layer, a nonmagnetic conductive layer in contact with the free magnetic layer, a pinned magnetic layer in contact with the nonmagnetic conductive layer, and an antiferromagnetic layer in contact with the pinned magnetic layer in that order on a substrate;
• forming a lift-off resist layer on the laminate;
• removing the region of the laminate which is not covered with the lift-off resist layer by ion milling so that the laminate has a trapezoidal cross-section;
• forming bias underlying layers by a first sputtering process on both inclined sides of the laminate and over the peripheral sections of the laminate while a sputtering target comprising Fe or an Fe-Co alloy is opposed to the substrate at a predetermined angle so that the thickness of the bias underlying layers on the inclined sides of the laminate is equal to or larger than the thickness of the bias underlying layers over the peripheral sections of the laminate;
• forming bias layers on the bias underlying layers by a second sputtering process;
• and
• forming electrode layers on the bias layers by a third sputtering process.