Inventors list

Assignees list

Classification tree browser

Top 100 Inventors

Top 100 Assignees


Min Li, Dublin US

Min Li, Dublin, CA US

Patent application numberDescriptionPublished
20080219042Magnetic memory cell - By inserting a spin polarizing layer (typically pure iron) within the free layer of a MTJ or GMR memory cell, dR/R can be improved without significantly affecting other free layer properties such as Hc. Additional performance improvements can be achieved by also inserting a surfactant layer (typically oxygen) within the free layer.09-11-2008
20080220156CPP with elongated pinned layer - CPP magnetic read head designs have been improved by increasing the length of the AFM layer relative to that of both the free and spacer layers. The length of the pinned layer is also increased, but by a lesser amount, an abutting conductive layer being inserted to fill the remaining space over the AFM layer. The extended pinned layer increases the probability of spin interaction while the added conducting layer serves to divert sensor current away from the bottom magnetic shield which now is no longer needed for use as a lead.09-11-2008
20080246103MR device with surfactant layer within the free layer - The dR/R ratios of TMR and GMR devices, having a FeCo/NiFe type of free layer, have been significantly increased by inserting a suitable surfactant layer within (as opposed to above or below) the free layer. Our preferred surfactant material has been oxygen but similar-acting materials could be substituted. The concept can be applied to GMR CPP, CIP, and CCP sensor designs.10-09-2008
20080253035Self-aligned full side shield PMR and method to make it - A process for forming the write pole of a PMR head is described. This write pole is symmetrically located relative to its side shields, This is accomplished, not through optical alignment, but by coating the pole with a uniform layer of non-magnetic material of a predetermined and precise thickness, followed by the formation of the shield layer around this.10-16-2008
20080260943Process for composite free layer in CPP GMR or TMR device - The conventional free layer in a CPP GMR or TMR read head has been replaced by a tri-layer laminate comprising Co rich CoFe, moderately Fe rich NiFe, and heavily Fe rich NiFe. The result is an improved device that has a higher MR ratio than prior art devices, while still maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is described.10-23-2008
20080278864Novel CPP device with an enhanced dR/R ratio - A CPP-GMR spin valve having a composite spacer layer comprised of at least one metal (M) layer and at least one semiconductor or semi-metal (S) layer is disclosed. The composite spacer may have a M/S, S/M, M/S/M, S/M/S, M/S/M/S/M, or a multilayer (M/S/M)11-13-2008
20080297945Method to make a perpendicular magnetic recording head with a bottom side shield - A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a separated pair of bottom side shields and shielded from above by an upper shield. The bottom side shields surround a lower portion of the pole tip while the upper portion of the pole tip is surrounded by non-magnetic layers. The bottom shields and the non-magnetic layer form wedge-shaped trench in which the pole tip is formed by a self-aligned plating process. The wedge shape is formed by a RIE process using specific gases applied through a masking layer formed of material that has a slower etch rate than the non-magnetic material or the shield material. A masking layer of Ta, Ru/Ta, TaN or Ti, formed on a non-magnetic layer of alumina that is formed on a shield layer of NiFe and using RIE gases of CH12-04-2008
20080299679Low resistance tunneling magnetoresistive sensor with composite inner pinned layer - A high performance TMR sensor is fabricated by employing a composite inner pinned (AP12-04-2008
20080316657TMR or CPP structure with improved exchange properties - 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.12-25-2008
20090009907Laminated film for head applications - A laminated main pole layer is disclosed in which a non-AFC scheme is used to break the magnetic coupling between adjacent high moment layers and reduce remanence in a hard axis direction while maintaining a high magnetic moment and achieving low values for Hch, Hce, and Hk. An amorphous material layer with a thickness of 3 to 20 Angstroms and made of an oxide, nitride, or oxynitride of one or more of Hf, Zr, Ta, Al, Mg, Zn, or Si is inserted between adjacent high moment stacks. The laminated structure also includes an alignment layer below each high moment layer within each stack. In one embodiment, a Ru coupling layer is inserted between two high moment layers in each stack to introduce an AFC scheme. An uppermost Ru layer is used as a CMP stop layer. A post annealing process may be employed to further reduce the anisotropy field (Hk).01-08-2009
20090059441CPP device with improved current confining structure and process - Plasma nitridation, in place of plasma oxidation, is used for the formation of a CCP layer. Al, Mg, Hf, etc. all form insulating nitrides under these conditions. Maintaining the structure at a temperature of at least 150° C. during plasma nitridation and/or performing post annealing at a temperature of 220° C. or higher, ensures that no copper nitride can form. Additionally, unintended oxidation by molecular oxygen of the exposed magnetic layers (mainly the pinned and free layers) is also avoided03-05-2009
20090091865CPP device with uniformity improvements - 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.04-09-2009
20090121710Novel free layer design for TMR/CPP device - A TMR sensor and a CPP GMR sensor all include a free layer that is of the form CoFe05-14-2009
20090122450TMR device with low magnetostriction free layer - A high performance TMR sensor is fabricated by employing a free layer comprised of CoB05-14-2009
20090161266TMR device with surfactant layer on top of cofexby/cofez inner pinned layer - 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 CoFe06-25-2009
20090165288TMR device with surfactant layer on top of CoFexBy/CoFez inner pinned layer - 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 CoFe07-02-2009
20090194833TMR device with Hf based seed layer - 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 %.08-06-2009
20090251829Seed layer for TMR or CPP-GMR sensor - A composite seed layer that reduces the shield to shield distance in a read head while improving Hex and Hex/Hc is disclosed and has a SM/A/SM/B configuration in which the SM layers are soft magnetic layers, the A layer is made of at least one of Co, Fe, Ni, and includes one or more amorphous elements, and the B layer is a buffer layer that contacts the AFM layer in the spin valve. The SM/A/SM stack together with the S10-08-2009
20090257151Thin seeded Co/Ni multilayer film with perpendicular anisotropy for spintronic device applications - A spin valve structure for a spintronic device 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)10-15-2009
20090269617Ultra low RA sensors - A high performance TMR sensor with a spacer including at least one Cu layer and one or more MgO layers is disclosed. Optionally, Cu may be replaced by one of Au, Zn, Ru, or Al. In addition, there may be a dopant such as Zn, Mn, Al, Cu, Ni, Cd, Cr, Ti, Zr, Hf, Ru, Mo, Nb, Co, or Fe in the MgO layer. In an alternative embodiment, the MgO layer may be replaced by other low band gap insulating or semiconductor materials. A resonant tunneling mechanism is believed to be responsible for achieving an ultra-low RA of <0.4 μohm-cm10-29-2009
20090279213Stabilized shields for magnetic recording heads - A basic design is disclosed for bottom shield (S11-12-2009
20090314632FCC-like trilayer AP2 structure for CPP GMR EM improvement - A method of forming a CPP-GMR spin valve having a pinned layer with an AP2/coupling/AP1 configuration is disclosed wherein the AP2 portion is a FCC-like trilayer having a composition represented by Co12-24-2009
20090323227Ta/W film as heating device for dynamic fly height adjustment - A dynamic fly heater (DFH) for improved lifetime and better film uniformity is disclosed for a magnetic head. The heater has a lower amorphous Ta layer and an upper W layer to promote small grain size and reduced electro-migration. The composite film is especially advantageous for heaters greater than 1000 Angstroms thick where dR/R is difficult to control in the prior art. The DFH may be a (Ta/W)12-31-2009
20100019333Low resistance tunneling magnetoresistive sensor with composite inner pinned layer - A high performance TMR sensor is fabricated by employing a composite inner pinned (AP1) layer in an AP2/Ru/AP1 pinned layer configuration. In one embodiment, there is a 10 to 80 Angstrom thick lower CoFeB or CoFeB alloy layer on the Ru coupling layer, a and 5 to 50 Angstrom thick Fe or Fe alloy layer on the CoFeB or CoFeB alloy, and a 5 to 30 Angstrom thick Co or Co rich alloy layer formed on the Fe or Fe alloy. A MR ratio of about 48% with a RA of <2 ohm-um01-28-2010
20100037453Current confining layer for GMR device - Concerns about inadequate electromigration robustness in CCP CPP GMR devices have been overcome by adding magnesium to the current confining structures that are presently in use. In one embodiment the alumina layer, in which the current carrying copper regions are embedded, is fully replaced by a magnesia layer. In other embodiments, alumina is still used but a layer of magnesium is included within the structure before it is subjected to ion assisted oxidation.02-18-2010
20100073827TMR device with novel free layer structure - A TMR sensor that includes a free layer having at least one B-containing (BC) layer made of CoFeB, CoFeBM, CoB, COBM, or CoBLM, and a plurality of non-B containing (NBC) layers made of CoFe, CoFeM, or CoFeLM is disclosed where L and M are one of Ni, Ta, Ti, W, Zr, Hf, Tb, or Nb. One embodiment is represented by (NBC/BC)03-25-2010
20100073828TMR device with novel free layer - A TMR sensor with a free layer having a FL1/FL2/FL3 configuration is disclosed in which FL1 is FeCo or a FeCo alloy with a thickness between 2 and 15 Angstroms. The FL2 layer is made of CoFeB or a CoFeB alloy having a thickness from 2 to 10 Angstroms. The FL3 layer is from 10 to 100 Angstroms thick and has a negative λ to offset the positive λ from FL1 and FL2 layers and is comprised of CoB or a CoBQ alloy where Q is one of Ni, Mn, Tb, W, Hf, Zr, Nb, and Si. Alternatively, the FL3 layer may be a composite such as CoB/CoFe, (CoB/CoFe)03-25-2010
20100091414Method for manufacturing a magneto-resistance effect element and magnetic recording and reproducing apparatus - A method for manufacturing a magneto-resistance effect element is provided. The magneto-resistance effect element includes a first magnetic layer including a ferromagnetic material, a second magnetic layer including a ferromagnetic material and a spacer layer provided between the first magnetic layer and the second magnetic layer, the spacer layer having an insulating layer and a conductive portion penetrating through the insulating layer. The method includes: forming a film to be a base material of the spacer layer; performing a first treatment using a gas including at least one of oxygen molecules, oxygen atoms, oxygen ions, oxygen plasma and oxygen radicals on the film; and performing a second treatment using a gas including at least one of krypton ions, krypton plasma, krypton radicals, xenon ions, xenon plasma and xenon radicals on the film submitted to the first treatment.04-15-2010
20100091415Method for manufacturing a magneto-resistance effect element and magnetic recording and reproducing apparatus - A method for manufacturing a magneto-resistance effect element is provided. The magneto-resistance effect element includes a first magnetic layer including a ferromagnetic material, a second magnetic layer including a ferromagnetic material and a spacer layer provided between the first magnetic layer and the second magnetic layer, the spacer layer having an insulating layer and a conductive portion penetrating through the insulating layer. The method includes: forming a film to be a base material of the spacer layer; performing a first treatment using a gas including at least one of oxygen molecules, oxygen atoms, oxygen ions, oxygen plasma and oxygen radicals on the film; and performing a second treatment using a gas including at least one of nitrogen ions, nitrogen atoms, nitrogen plasma, and nitrogen radicals on the film submitted to the first treatment.04-15-2010
20100092803Method for manufacturing a magneto-resistance effect element and magnetic recording and reproducing apparatus - A method for manufacturing a magneto-resistance effect element is provided. The magneto-resistance effect element includes a first magnetic layer including a ferromagnetic material, a second magnetic layer including a ferromagnetic material and a spacer layer provided between the first magnetic layer and the second magnetic layer, the spacer layer having an insulating layer and a conductive portion penetrating through the insulating layer. The method includes: forming a film to be a base material of the spacer layer; performing a first treatment using a gas including at least one of oxygen molecules, oxygen atoms, oxygen ions, oxygen plasma and oxygen radicals on the film; and performing a second treatment using a gas including at least one of hydrogen molecules, hydrogen atoms, hydrogen ions, hydrogen plasma, hydrogen radicals, deuterium molecules, deuterium atoms, deuterium ions, deuterium plasma and deuterium radicals on the film submitted to the first treatment.04-15-2010
20100119874Laminated high moment film for head applications - A laminated high moment film with a non-AFC configuration is disclosed that can serve as a seed layer for a main pole layer or as the main pole layer itself in a PMR writer. The laminated film includes a plurality of (B/M) stacks where B is an alignment layer and M is a high moment layer. Adjacent (B/M) stacks are separated by an amorphous layer that breaks the magnetic coupling between adjacent high moment layers and reduces remanence in a hard axis direction while maintaining a high magnetic moment and achieving low values for Hch, Hce, and Hk. The amorphous material layer may be made of an oxide, nitride, or oxynitride of one or more of Hf, Zr, Ta, Al, Mg, Zn, Ti, Cr, Nb, or Si, or may be Hf, Zr, Ta, Nb, CoFeB, CoB, FeB, or CoZrNb. Alignment layers are FCC soft ferromagnetic materials or non-magnetic FCC materials.05-13-2010
20100123208MR device with synthetic free layer structure - A magneto-resistive device having a large output signal as well as a high signal-to-noise ratio is described along with a process for forming it. This improved performance was accomplished by expanding the free layer into a multilayer laminate comprising at least three ferromagnetic layers separated from one another by antiparallel coupling layers. The ferromagnetic layer closest to the transition layer must include CoFeB while the furthermost layer is required to have low Hc as well as a low and negative lambda value. One possibility for the central ferromagnetic layer is NiFe but this is not mandatory.05-20-2010
20100177449TMR device with novel free layer stucture - A composite free layer having a FL1/insertion/FL2 configuration is disclosed for achieving high dR/R, low RA, and low λ in TMR or GMR sensors. Ferromagnetic FL1 and FL2 layers have (+) λ and (−) λ values, respectively. FL1 may be CoFe, CoFeB, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, or Nb. FL2 may be CoFe, NiFe, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, Nb, or B. The thin insertion layer includes at least one magnetic element such as Co, Fe, and Ni, and at least one non-magnetic element selected from Ta, Ti, W, Zr, Hf, Nb, Mo, V, Cr, or B. In a TMR stack with a MgO tunnel barrier, dR/R>60%, λ˜1×1007-15-2010
20100276272Method for fabricating a high coercivity hard bias structure for magnetoresistive sensor - 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.11-04-2010
20100304185Low resistance tunneling magnetoresistive sensor with natural oxidized double MgO barrier - 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-um12-02-2010
20100320076Low resistance tunneling magnetoresistive sensor with natural oxidized double MgO barrier - 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-um12-23-2010
20100330395Thin seeded Co/Ni multiplayer film with perpendicular anisotropy for read head sensor stabilization - 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)12-30-2010
20110096443MTJ incorporating CoFe/Ni multilayer film with perpendicular magnetic anisotropy for MRAM application - 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)04-28-2011
20110117388Multiple CCP layers in magnetic read head devices - 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.05-19-2011
20110146060Method to make a perpendicular magnetic recording head with a side write shield - A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a separated pair of side shields and shielded from above by an upper shield. The side shields are formed by a RIE process using specific gases applied to a shield layer through a masking layer formed of material that has a slower etch rate than the shield material. A masking layer of Ta, Ru/Ta, TaN or Ti, formed on a shield layer of NiFe and using RIE gases of CH06-23-2011

Patent applications by Min Li, Dublin, CA US