Abstract: A magnetoresistive sensor having a substrate that has been treated with nitrogen (nitrogenated). The nitrogenated substrate includes an alumina base layer and a thin top layer of crystalline alumina that has had a very small amount of nitrogen deposited on top. The amount of nitrogen deposited on top of the alumina is less than or equal to two monolayer, and is preferably less than or monolayer. The amount of nitrogen deposited on top of the alumina substrate is not enough to constitute a layer of nitrogen, but affects the structure of the alumina to cause the alumina to have a desired crystalline structure and an extremely smooth surface.

Abstract: A magnetoresistive sensor having a Ta cap layer with nitrogen added in situ during deposition. The nitrogen in the cap layer can be formed by depositing a Ta cap layer in a sputter deposition chamber having a small amount of nitrogen in an Ar atmosphere. The resulting nitrogenated cap layer exhibits reduced specular scattering, which results in improved magnetic performance of the magnetoresistive sensor.

Abstract: Methods and apparatus provide a magnetic head that includes a magnetoresistive read sensor. A remanence of a pinned layer within the read sensor can be improved without substantially altering other physical or magnetic properties of the read sensor. Changing a sputtering gas flow rate during deposition of an antiferromagnetic layer within the read sensor can lower the remanence of the pinned layer and hence a remanence of the read sensor.

Abstract: A method for controlling magnetostriction in a free layer of a magnetoresistive sensor. A pinned layer structure is deposited and then a spacer layer, preferably Cu is deposited. Oxygen is introduced into the spacer layer. The oxygen can be introduced either during the deposition of the spacer layer or after the spacer layer has been deposited. A free layer structure is then deposited over the spacer layer. A capping layer such as Ta can be deposited over the free layer structure. The sensor is annealed to set the magnetization of the pinned layer. In the process of annealing the sensor the oxygen migrates out of the spacer. After annealing, no significant amount of oxygen is present in either the spacer layer or the free layer structure, and only trace amounts of oxygen are present in the Ta capping layer.

Abstract: A magnetoresistive sensor having a substrate that has been treated with nitrogen (nitrogenated) and having a Ta cap layer with nitrogen added in situ during deposition. The nitrogenated substrate includes an alumina base layer and a thin top layer of crystalline alumina that has had a very small amount of nitrogen deposited on top. The amount of nitrogen deposited on top of the alumina is less than or equal to two monolayer, and is preferably less than on monolayer. The amount of nitrogen deposited on top of the alumina substrate is riot enough to constitute a layer of nitrogen, but affects the structure of the alumina to cause the alumina to have a desired crystalline structure and an extremely smooth surface. The nitrogen in the cap layer can be formed by depositing a Ta cap layer in a sputter deposition chamber having a small amount of nitrogen in an Ar atmosphere.