Patent application number | Description | Published |
20080217710 | Novel SyAF structure to fabricate Mbit MTJ MRAM - A MTJ that minimizes error count (EC) while achieving high MR value, low magnetostriction, and a RA of about 1100 Ω-μm | 09-11-2008 |
20080225583 | Spin transfer MRAM device with novel magnetic free layer - We describe a CPP MTJ MRAM element that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes a tunneling barrier layer of MgO and a non-magnetic CPP layer of Cu or Cr and utilizes a novel free layer comprising a thin layer of Ta or Hf sandwiched by layers of CoFeB. The device is characterized by values of DR/R between approximately 95% and 105%. | 09-18-2008 |
20080239589 | Spin transfer MRAM device with novel magnetic synthetic free layer - We describe a CPP MTJ MRAM element that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes a tunneling barrier layer of MgO and a non-magnetic CPP layer of Cu or Cr and utilizes a novel synthetic free layer having three ferromagnetic layers mutually exchange coupled in pairwise configurations. The free layer comprises an inner ferromagnetic and two outer ferromagnetic layers, with the inner layer being ferromagnetically exchange coupled to one outer layer and anti-ferromagnetically exchange coupled to the other outer layer. The ferromagnetic coupling is very strong across an ultra-thin layer of Ta, Hf or Zr of thickness preferably less than 0.4 nm. | 10-02-2008 |
20090027810 | High performance MTJ element for STT-RAM and method for making the same - We describe the structure and method of forming a STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that comprises an amorphous layer of Co | 01-29-2009 |
20090108383 | High performance MTJ element for conventional MRAM and for STT-RAM and a method for making the same - A STT-RAM MTJ that minimizes spin-transfer magnetization switching current (Jc) is disclosed. The MTJ has a MgO tunnel barrier layer formed with a natural oxidation process to achieve a low RA (10 ohm-um | 04-30-2009 |
20090246557 | Low switching current dual spin filter (DSF) element for STT-RAM and a method for making the same - A dual spin filter that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R in STT-RAM devices is disclosed. The bottom spin valve has a MgO tunnel barrier layer formed with a natural oxidation process to achieve low RA, a CoFe/Ru/CoFeB—CoFe pinned layer, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel (NCC) layer to minimize Jc | 10-01-2009 |
20090256220 | Low switching current MTJ element for ultra-high STT-RAM and a method for making the same - A STT-RAM MTJ that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R is disclosed. The MTJ has a MgO tunnel barrier formed by natural oxidation to achieve a low RA, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel layer to minimize Jc | 10-15-2009 |
20090325319 | Novel capping layer for a magnetic tunnel junction device to enhance dR/R and a method of making the same - An MTJ in an MRAM array or TMR read head is disclosed in which a low magnetization capping layer is a composite having a NiFeHf inner layer formed on a NiFe or CoFeB/NiFe free layer, a Ta middle layer, and a Ru outer layer on the Ta layer. For example, a low magnetization NiFeHf layer is achieved by co-sputtering NiFe and Hf targets with a forward power of 400 W and 200 W, respectively. A higher Hf content increases the oxygen gettering power of the NiFeHf layer and the thickness is modified to change dR/R, RA, and magnetostriction values. A so-called dead layer between the free layer and capping layer is restored by incorporating a NiFeHf layer on the free layer to improve lattice matching. The Fe content in the NiFe target used to make the NiFeHf layer is preferably the same as in the NiFe free layer. | 12-31-2009 |
20100006960 | Novel magnetic tunnel junction (MTJ) to reduce spin transfer magnetizaton switching current - A MTJ that minimizes spin-transfer magnetization switching current (Jc) in a Spin-RAM to <1×10 | 01-14-2010 |
20100009467 | Novel magnetic tunnel junction (MTJ) to reduce spin transfer magnetization switching current - A MTJ that minimizes spin-transfer magnetization switching current (Jc) in a Spin-RAM to <1×10 | 01-14-2010 |
20100065935 | Structure and method to fabricate high performance MTJ devices for spin-transfer torque (STT)-RAM - A STT-RAM MTJ is disclosed with a MgO tunnel barrier formed by a NOX process, a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel layer to minimize Jc | 03-18-2010 |
20100136713 | Hafnium doped cap and free layer for mram device - A high performance MTJ, and a process for manufacturing it, are described. A capping layer of NiFeHf is used to getter oxygen out of the free layer, thereby increasing the sharpness of the free layer-tunneling layer interface. The free layer comprises two NiFe layers whose magnetostriction constants are of opposite sign, thereby largely canceling one another. | 06-03-2010 |
20100176429 | MRAM with storage layer and super-paramagnetic sensing layer - An MRAM is disclosed that has a MTJ comprised of a ferromagnetic layer with a magnetization direction along a first axis, a super-paramagnetic (SP) free layer, and an insulating layer formed therebetween. The SP free layer has a remnant magnetization that is substantially zero in the absence of an external field, and in which magnetization is roughly proportional to an external field until reaching a saturation value. In one embodiment, a separate storage layer is formed above, below, or adjacent to the MTJ and has uniaxial anisotropy with a magnetization direction along its easy axis which parallels the first axis. In a second embodiment, the storage layer is formed on a non-magnetic conducting spacer layer within the MTJ and is patterned simultaneously with the MTJ. The SP free layer may be multiple layers or laminated layers of CoFeB. The storage layer may have a SyAP configuration and a laminated structure. | 07-15-2010 |
20100176470 | NOVEL FREE LAYER/CAPPING LAYER FOR HIGH PERFORMANCE MRAM MTJ - An MTJ MRAM cell and its method of formation are described. The cell includes a composite free layer having the general form (Ni | 07-15-2010 |
20100178715 | MRAM with storage layer and super-paramagnetic sensing layer - An MRAM is disclosed that has a MTJ comprised of a ferromagnetic layer with a magnetization direction along a first axis, a super-paramagnetic (SP) free layer, and an insulating layer formed therebetween. The SP free layer has a remnant magnetization that is substantially zero in the absence of an external field, and in which magnetization is roughly proportional to an external field until reaching a saturation value. In one embodiment, a separate storage layer is formed above, below, or adjacent to the MTJ and has uniaxial anisotropy with a magnetization direction along its easy axis which parallels the first axis. In a second embodiment, the storage layer is formed on a non-magnetic conducting spacer layer within the MTJ and is patterned simultaneously with the MTJ. The SP free layer may be multiple layers or laminated layers of CoFeB. The storage layer may have a SyAP configuration and a laminated structure. | 07-15-2010 |
20100258888 | High performance MTJ element for STT-RAM and method for making the same - An STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that comprises an amorphous layer of Co | 10-14-2010 |
20100258889 | High performance MTJ elements for STT-RAM and method for making the same - An STT-MTJ MRAM cell utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The cell includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a composite tri-layer free layer that comprises an amorphous layer of Co | 10-14-2010 |
20100261295 | High performance MTJ element for STT-RAM and method for making the same - A method of forming a STT-MTJ MRAM cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes an IrMn pinning layer, a SyAP pinned layer, a naturally oxidized, crystalline MgO tunneling barrier layer that is formed on an Ar-ion plasma smoothed surface of the pinned layer and, in one embodiment, a free layer that comprises an amorphous layer of Co | 10-14-2010 |
20110014500 | Structure and method to fabricate high performance MTJ devices for spin-transfer torque (STT)-RAM application - A STT-RAM MTJ is disclosed with a MgO tunnel barrier formed by natural oxidation and containing an oxygen surfactant layer to form a more uniform MgO layer and lower breakdown distribution percent. A CoFeB/NCC/CoFeB composite free layer with a middle nanocurrent channel layer minimizes Jc | 01-20-2011 |
20110076785 | Process to fabricate bottom electrode for MRAM device - Formation of a bottom electrode for an MTJ device on a silicon nitride substrate is facilitated by including a protective coating that is partly consumed during etching of the alpha tantalum portion of said bottom electrode. Adhesion to SiN is enhanced by using a TaN/NiCr bilayer as “glue”. | 03-31-2011 |
20110096443 | MTJ 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 |
20110133300 | Bottom electrode for MRAM device - A multi-layered bottom electrode for an MTJ device on a silicon nitride substrate is described. It comprises a bilayer of alpha tantalum on ruthenium which in turn lies on a nickel chrome layer over a second tantalum layer. | 06-09-2011 |
20120040207 | Low switching current dual spin filter (DSF) element for STT-RAM and a method for making the same - A dual spin filter that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R in STT-RAM devices is disclosed. The bottom spin valve has a MgO tunnel barrier layer formed with a natural oxidation process to achieve low RA, a CoFe/Ru/CoFeB—CoFe pinned layer, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel (NCC) layer to minimize Jc | 02-16-2012 |
20120058575 | Low switching current dual spin filter (DSF) element for STT-RAM and a method for making the same - A dual spin filter that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R in STT-RAM devices is disclosed. The bottom spin valve has a MgO tunnel barrier layer formed with a natural oxidation process to achieve low RA, a CoFe/Ru/CoFeB—CoFe pinned layer, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel (NCC) layer to minimize Jc | 03-08-2012 |
20120135273 | Structure and method for enhancing interfacial perpendicular anisotropy in CoFe(B)/MgO/CoFe(B) Magnetic Tunnel Junctions - A STT-RAM MTJ is disclosed with a MgO tunnel barrier formed by natural oxidation process. A Co | 05-31-2012 |
20120181537 | Magnetic Tunnel Junction for MRAM applications - A MTJ in an MRAM array is disclosed with a composite free layer having a lower crystalline layer contacting a tunnel barrier and an upper amorphous NiFeX layer for improved bit switching performance. The crystalline layer is Fe, Ni, or FeB with a thickness of at least 6 Angstroms which affords a high magnetoresistive ratio. The X element in the NiFeX layer is Mg, Hf, Zr, Nb, or Ta with a content of 5 to 30 atomic %. NiFeX thickness is preferably between 20 to 40 Angstroms to substantially reduce bit line switching current and number of shorted bits. In an alternative embodiment, the crystalline layer may be a Fe/NiFe bilayer. Optionally, the amorphous layer may have a NiFeM | 07-19-2012 |
20130154038 | High Performance MTJ Element for Conventional MRAM and for STT-RAM and a Method for Making the Same - A STT-RAM MTJ that minimizes spin-transfer magnetization switching current (Jc) is disclosed. The MTJ has a MgO tunnel barrier layer formed with a natural oxidation process to achieve a low RA (10 ohm-um | 06-20-2013 |
20130175644 | Spin Torque Transfer Magnetic Tunnel Junction Fabricated with a Composite Tunneling Barrier Layer - A STT-RAM MTJ is disclosed with a composite tunnel barrier comprised of a CoMgO layer that contacts a pinned layer and a MgO layer which contacts a free layer. A CoMg layer with a Co content between 20 and 40 atomic % is deposited on the pinned layer and is then oxidized to produce Co nanoconstrictions within a MgO insulator matrix. The nanoconstrictions control electromigration of Co into an adjoining MgO layer. The free layer may comprise a nanocurrent channel (NCC) layer such as FeSiO or a moment dilution layer such as Ta between two ferromagnetic layers. Furthermore, a second CoMgO layer or a CoMgO/MgO composite may serve as a perpendicular Hk enhancing layer formed between the free layer and a cap layer. One or both of the pinned layer and free layer may exhibit in-plane anisotropy or perpendicular magnetic anisotropy. | 07-11-2013 |
20140099735 | Structure and Method to Fabricate High Performance MTJ Devices for Spin-Transfer Torque (STT)-RAM Application - A STT-RAM MTJ is disclosed with a MgO tunnel barrier formed by natural oxidation and containing an oxygen surfactant layer to form a more uniform MgO layer and lower breakdown distribution percent. A CoFeB/NCC/CoFeB composite free layer with a middle nanocurrent channel layer minimizes Jc | 04-10-2014 |
20140306305 | Magnetic Tunnel Junction for MRAM Applications - A MTJ in an MRAM array is disclosed with a composite free layer having a lower crystalline layer contacting a tunnel barrier and an upper amorphous NiFeX layer for improved bit switching performance. The crystalline layer is Fe, Ni, or FeB with a thickness of at least 6 Angstroms which affords a high magnetoresistive ratio. The X element in the NiFeX layer is Mg, Hf, Zr, Nb, or Ta with a content of 5 to 30 atomic %. NiFeX thickness is preferably between 20 to 40 Angstroms to substantially reduce bit line switching current and number of shorted bits. In an alternative embodiment, the crystalline layer may be a Fe/NiFe bilayer. Optionally, the amorphous layer may have a NiFeM | 10-16-2014 |