Abstract: An improved CPP magnetic read device whose oxide barrier comprises at least two separate CCP layers is disclosed. These two CCP layers differ in the PIT and IAO treatments that they received relative to the PIT/IAO treatment that would be used when only a single CCP layer is formed.

Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?s values. A higher than normal Fe content in the CoFe layer improves the MR ratio by ?16% compared with conventional CoFe/NiFe free layers in which the Fe content in CoFe is typically <20 atomic % and the Ni content in NiFe is <85 atomic %. The CPP-GMR performance may also be optimized by incorporating a confining current path layer in the copper spacer between the pinned layer and free layer. For a pinned layer with an AP2/Ru/AP1 configuration, the spin valve performance is further improved by an AP1 layer comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.

Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?S values. A higher than normal Fe content in the CoFe layer improves the MR ratio by ?16% compared with conventional CoFe/NiFe free layers in which the Fe content in CoFe is typically <20 atomic % and the Ni content in NiFe is <85 atomic %. The CPP-GMR performance may also be optimized by incorporating a confining current path layer in the copper spacer between the pinned layer and free layer. For a pinned layer with an AP2/Ru/AP1 configuration, the spin valve performance is further improved by an AP1 layer comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.

Abstract: A high performance TMR element is fabricated by inserting an oxygen surfactant layer (OSL) between a pinned layer and AlOx tunnel barrier layer in a bottom spin valve configuration. The pinned layer preferably has a SyAP configuration with an outer pinned layer, a Ru coupling layer, and an inner pinned layer comprised of CoFeXBY/CoFeZ wherein x=0 to 70 atomic %, y=0 to 30 atomic %, and z=0 to 100 atomic %. The OSL is formed by treating the CoFeZ layer with oxygen plasma. The AlOx tunnel barrier has improved uniformity of about 2% across a 6 inch wafer and can be formed from an Al layer as thin as 5 Angstroms. As a result, the Hin value can be decreased by ? to about 32 Oe. A dR/R of 25% and a RA of 3 ohm-cm2 have been achieved for TMR read head applications.

Abstract: A novel CCP scheme is disclosed for a CPP-GMR sensor in which an amorphous metal/alloy layer such as Hf is inserted between a lower Cu spacer and an oxidizable layer such as Al, Mg, or AlCu prior to performing a pre-ion treatment (PIT) and ion assisted oxidation (IAO) to transform the amorphous layer into a first metal oxide template and the oxidizable layer into a second metal oxide template both having Cu metal paths therein. The amorphous layer promotes smoothness and smaller grain size in the oxidizable layer to minimize variations in the metal paths and thereby improves dR/R, R, and dR uniformity by 50% or more. An amorphous Hf layer may be used without an oxidizable layer, or a thin Cu layer may be inserted in the CCP scheme to form a Hf/PIT/IAO or Hf/Cu/Al/PIT/IAO configuration. A double PIT/IAO process may be used as in Hf/PIT/IAO/Al/PIT/IAO or Hf/PIT/IAO/Hf/PIT/IAO schemes.

Abstract: An insertion layer is provided between an AFM layer and an AP2 pinned layer in a GMR or TMR element to improve exchange coupling properties by increasing Hex and the Hex/Hc ratio without degrading the MR ratio. The insertion layer may be a 1 to 15 Angstrom thick amorphous magnetic layer comprised of at least one element of Co, Fe, or Ni, and at least one element having an amorphous character selected from B, Zr, Hf, Nb, Ta, Si, or P, or a 1 to 5 Angstrom thick non-magnetic layer comprised of Cu, Ru, Mn, Hf, or Cr. Preferably, the content of the one or more amorphous elements in the amorphous magnetic layer is less than 40 atomic %. Optionally, the insertion layer may be formed within the AP2 pinned layer. Examples of an insertion layer are CoFeB, CoFeZr, CoFeNb, CoFeHf, CoFeNiZr, CoFeNiHf, and CoFeNiNbZr.

Abstract: An improved CPP magnetic read device whose oxide barrier comprises at least two separate CCP layers is disclosed. These two CCP layers differ in the PIT and IAO treatments that they received relative to the PIT/IAO treatment that would be used when only a single CCP layer is formed.

Abstract: A MTJ for a spintronic device is disclosed and includes a thin composite seed layer made of at least Ta and a metal layer having fcc(111) or hcp(001) texture as in Ta/Ti/Cu to enhance perpendicular magnetic anisotropy (PMA) in an overlying laminated layer with a (CoFe/Ni)X, (Co/NiFe)X, (Co/NiCo)X, (CoFe/NiFe)X, or (CoFe/NiCo)X composition where x is from 5 to 30. In one embodiment, a CPP-TMR spin valve has one or both of a laminated free layer and laminated reference layer with the aforementioned compositions. The MTJ includes an interfacial layer made of CoFeB, CoFeB/CoFe, or CoFe/CoFeB between each laminated structure and the tunnel barrier. The laminated layers are deposited by a low power and high Ar pressure process to avoid damaging interfaces between adjoining layers. Annealing occurs at 220° C. to 400° C. A laminated layer with high PMA may also be included in one or more layers of a spin transfer oscillator.

Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?S values. A small positive magnetostriction value in a Co75Fe25 layer is used to offset a negative magnetostriction value in a Ni90Fe10 layer. The CoFe layer is deposited on a sensor stack in which a seed layer, AFM layer, pinned layer, and non-magnetic spacer layer are sequentially formed on a substrate. After a NiFe layer and capping layer are sequentially deposited on the CoFe layer, the sensor stack is patterned to give a sensor element with top and bottom surfaces and a sidewall connecting the top and bottom surfaces. Thereafter, a dielectric layer is formed adjacent to the sidewalls.

Abstract: A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.

Abstract: A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.

Abstract: Improved performance uniformity among CPP magnetic read devices that include an oxide barrier has been achieved by fabricating the oxide layer from at least two separately formed CCP layers. Each CCP layer is given its own PIT and IAO treatment which is of shorter duration than the PIT/IAO treatment that is used when only a single CCP layer is formed.

Abstract: A high performance TMR element is fabricated by inserting an oxygen surfactant layer (OSL) between a pinned layer and AlOx tunnel barrier layer in a bottom spin valve configuration. The pinned layer preferably has a SyAP configuration with an outer pinned layer, a Ru coupling layer, and an inner pinned layer comprised of CoFeXBY/CoFeZ wherein x=0 to 70 atomic %, y=0 to 30 atomic %, and z=0 to 100 atomic %. The OSL is formed by treating the CoFeZ layer with oxygen plasma. The AlOx tunnel barrier has improved uniformity of about 2% across a 6 inch wafer and can be formed from an Al layer as thin as 5 Angstroms. As a result, the Hin value can be decreased by ? to about 32 Oe. A dR/R of 25% and a RA of 3 ohm-cm2 have been achieved for TMR read head applications.

Abstract: A hard bias (HB) structure for producing longitudinal bias to stabilize a free layer in an adjacent spin valve is disclosed and includes a composite seed layer made of at least Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (Co/Ni)X laminated layer. The (Co/Ni)X HB layer deposition involves low power and high Ar pressure to avoid damaging Co/Ni interfaces and thereby preserves PMA. A capping layer is formed on the HB layer to protect against etchants in subsequent process steps. After initialization, magnetization direction in the HB layer is perpendicular to the sidewalls of the spin valve and generates an Mrt value that is greater than from an equivalent thickness of CoPt. A non-magnetic metal separation layer may be formed on the capping layer and spin valve to provide an electrical connection between top and bottom shields.

Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.

Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.

Abstract: A MTJ structure is disclosed in which the seed layer is made of a lower Ta layer, a middle Hf layer, and an upper NiFe or NiFeX layer where X is Co, Cr, or Cu. Optionally, Zr, Cr, HfZr, or HfCr may be employed as the middle layer and materials having FCC structures such as CoFe and Cu may be used as the upper layer. As a result, the overlying layers in a TMR sensor will be smoother and less pin dispersion is observed. The Hex/Hc ratio is increased relative to that for a MTJ having a conventional Ta/Ru seed layer configuration. The trilayer seed configuration is especially effective when an IrMn AFM layer is grown thereon and thereby reduces Hin between the overlying pinned layer and free layer. Ni content in the NiFe or NiFeX middle layer is above 30 atomic % and preferably >80 atomic %.

Abstract: A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that includes a mildly etched seed layer and a hard bias (HB) layer on the etched seed layer. The HB layer may contain one or more HB sub-layers stacked on a lower sub-layer which contacts the etched seed layer. Each HB sub-layer is mildly etched before depositing another HB sub-layer thereon. The etch may be performed in an IBD chamber and creates a higher concentration of nucleation sites on the etched surface thereby promoting a smaller HB average grain size than would be realized with no etch treatments. A smaller HB average grain size is responsible for increasing Hcr in a CoPt HB layer to as high as 2500 to 3000 Oe. Higher Hcr is achieved without changing the seed layer or HB material and without changing the thickness of the aforementioned layers.

Abstract: A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.

Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.