Hgst Netherlands, B.v.

Hitachi Global Storage Technologies Netherlands B.v.

Shekar B Chandrashekariaih

Jeffrey Childress

Matthew Joseph Carey

Stefan Maat

John C Read

Young-Suk Choi

A method for making a current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor that has a reference layer with low coercivity includes first depositing, within a vacuum chamber, a seed layer and an antiferromagnetic layer on a substrate without the application of heat. The substrate with deposited layers is then heated to between 200-600&#xb0; C. for between 1 to 120 minutes. The substrate with deposited layers is then cooled, preferably to room temperature (i.e., below 50&#xb0; C., but to at least below 100&#xb0; C., in the vacuum chamber. After cooling of the antiferromagnetic layer, the ferromagnetic reference layer is deposited on the antiferromagnetic layer. Then the substrate with deposited layers is removed from the vacuum chamber and subjected to a second annealing, in the presence of a magnetic field, by heating to a temperature between 200-400&#xb0; C. for between 0.5-50 hours.

Method for making a current-perpendicular-to-the-plane (CPP) magnetoresistive sensor having a low-coercivity reference layer

A magnetoresistive sensor that has a free layer with a face centered cubic, 100 crystal orientation formed on an underlayer structure that has been deposited in the presence of nitrogen. The free layer can be constructed of CoFe, Co(MnFe)X (where 0&#x2266;y&#x2266;1 and X is Si, Ge, Sn, Al, Ga, or a combination thereof), CoFeX (where X is Si, Ge, Sn, Al, Ga, or a combination thereof). The under-layer can include a layer of Ta, a Cu layer formed over the layer of Ta and deposited using a process gas comprising about 20 percent nitrogen and a layer of Ag deposited over the layer of Cu and deposited using a process gas comprising about 50 to 100 percent nitrogen.

[object Object]

A method for making a current-perpendicular-to the-plane giant magnetoresistance (CPP-GMR) sensor with a Heusler alloy pinned layer on the sensor's Mn-containing antiferromagnetic pinning layer uses two annealing steps. A layer of a crystalline non-Heusler alloy ferromagnetic material, like Co or CoFe, is deposited on the antiferromagnetic pinning layer and a layer of an amorphous X-containing ferromagnetic alloy, like a CoFeBTa layer, is deposited on the Co or CoFe crystalline layer. After a first in-situ annealing of the amorphous X-containing ferromagnetic alloy, the Heusler alloy pinned layer is deposited on the amorphous X-containing ferromagnetic layer and a second high-temperature annealing step is performed to improve the microstructure of the Heusler alloy pinned layer.

Method for making a current-perpendicular-to-the-plane (CPP) magnetoresistive sensor containing a ferromagnetic alloy requiring post-deposition annealing

A magnetoresistive sensor having a pinned layer that includes a first magnetic layer (AP1) a second magnetic layer (AP2) and an antiparallel coupling layer sandwiched between the AP1 and AP2 layers. The AP1 layer is adjacent to a layer of antiferromagnetic material (AFM layer) and is constructed so as to have a long spin diffusion length. The long spin diffusion length of the AP1 layer minimizes the negative GMR contribution of the AP1 layer, thereby increasing the overall GMR effect of the sensor.

Growing community of inventors

San Jose, CA, United States of America

Shekar B Chandrashekariaih