摘要:
A method of manufacturing a magnetoresistive head comprises forming a magnetoresistive structure with a magnetoresistive element with a first AFM element. Perform a first annealing step at a high temperature with a high magnetic field. Form the remaining MR structure including second AFM elements. Perform a low magnetic field (H.sub.ann) annealing step following the fabrication of the second AFM elements. Then perform a no externally applied field (H.sub.ann =0) annealing step at a high temperature to increase the H.sub.ex of the second AFM element to full strength, whereby the stability of the first AFM element is enhanced or increases its H.sub.ex if there were a decrease during the low magnetic field annealing step.
摘要:
A magnetic shielding element for a magnetic recording and sensing device which prevents the problem of pop-corn noise or covariance of amplitude noise in the magnetic sensing device. The shielding element has a layer of antiferromagnetic exchange material formed on a layer of single domain first ferromagnetic material. The single domain first ferromagnetic material is stabilized by the antiferromagnetic exchange material. A layer of non-magnetic metal is then formed on the layer of antiferromagnetic exchange material and a layer of second ferromagnetic material is formed on the layer of non-magnetic metal to complete the shielding element. When the single domains of the first ferromagnetic material are disturbed by the strong magnetic fields of a write cycle they relax with a relaxation time of pico seconds and are fully relaxed before a read cycle begins. The fully relaxed layer of first ferromagnetic material then shields the magnetic sensing device from magnetic field fluctuations caused by the slower relaxation of the domains in the layer of second ferromagnetic material during a read cycle.
摘要:
A cladding structure for a conductive line used to switch a free layer in a MTJ is disclosed and includes two cladding sidewalls on two sides of the conductive line, a top cladding portion on a side of the conductive line facing away from the MTJ, and a highly conductive, non-magnetic spacing control layer formed between the MTJ and conductive line. The spacing control layer has a thickness of 0.02 to 0.12 microns to maintain the distance separating free layer and conductive line between 0.03 and 0.15 microns. The spacing control layer is aligned parallel to the conductive line and contacts a plurality of MTJ elements in a row of MRAM cells. Half-select error problems are avoided while maintaining high write efficiency. A spacing control layer may be formed between a word line and a bottom electrode in a top pinned layer or dual pinned layer configuration.
摘要:
A cladding structure for a conductive line used to switch a free layer in a MTJ is disclosed and includes two cladding sidewalls on two sides of the conductive line, a top cladding portion on a side of the conductive line facing away from the MTJ, and a highly conductive, non-magnetic spacing control layer formed between the MTJ and conductive line. The spacing control layer has a thickness of 0.02 to 0.12 microns to maintain the distance separating free layer and conductive line between 0.03 and 0.15 microns. The spacing control layer is aligned parallel to the conductive line and contacts a plurality of MTJ elements in a row of MRAM cells. Half-select error problems are avoided while maintaining high write efficiency. A spacing control layer may be formed between a word line and a bottom electrode in a top pinned layer or dual pinned layer configuration.
摘要:
MTJ stacks formed using prior art processes often fail because of shorts between the pinned layer and the top electrode. This problem has been overcome by depositing a protective layer on the MTJ sidewalls followed by an inter-layer dielectric. Then planarizing until the protective layer is just exposed. Finally, an etching (or second CMP) process is used to selectively remove the protective layer from the top surface of the cap layer.
摘要:
A magnetic recording head is fabricated with a pole tip shielded laterally on its sides by a pair of symmetrically disposed side shields formed of porous heterogeneous material that contains non-magnetic inclusions. The non-magnetic inclusions, when properly incorporated within the magnetic matrix of the shields, promote the formation of flux loops within the shields that have portions that are parallel to the ABS and do not display locally disorganized and dynamic regions of flux during the creation of magnetic transitions within the recording medium by the magnetic pole. These flux loop portions, combine with the magnetic flux emerging from the main pole to create a net writing field that significantly reduces adjacent track erasures (ATE) and wide area erasures (WATE).
摘要:
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 Jc0 while enabling thermal stability, write voltage, read voltage, and Hc values that satisfy 64 Mb design requirements. The NCC layer has RM grains in an insulator matrix where R is Co, Fe, or Ni, and M is a metal such as Si or Al. NCC thickness is maintained around the minimum RM grain size to avoid RM granules not having sufficient diameter to bridge the distance between upper and lower CoFeB layers. A second NCC layer and third CoFeB layer may be included in the free layer or a second NCC layer may be inserted below the Ru capping layer.
摘要:
A PMR writer is disclosed with an all wrap around design wherein the leading shield, side shields, and composite trailing shield are comprised of an anisotropic (−Ku) magnetic layer, and where the leading shield and side shields adjoin a gap layer. The composite shield has a first layer made of an isotropic magnetic material adjoining the write gap, and the anisotropic (−Ku) layer adjoins the first trailing shield layer on a side opposite the write gap. The main pole may have a tapered leading side and a tapered trailing side with the anisotropic (−Ku) leading shield and trailing shield layers extending a greater distance from the ABS than the ends of the tapered main pole sides. Adjacent track erasure is minimized while on-track write field and field gradient are improved.
摘要:
An MRAM array structure and a method of its operation that is not subject to accidental writing on half-selected elements. Each element of the MRAM is an MTJ (magnetic tunneling junction) cell operating in accord with an STT (spin torque transfer) scheme for changing its free layer magnetization state and each cell is patterned to have a C-shape in the horizontal plane. The cell thereby operates by C-mode switching to provide stability against accidental writing by half-selection. During operation, switching of a cell's magnetization is accomplished with the assist of the pulsed magnetic fields of additional word lines that are formed either orthogonal to or parallel to the existing bit lines and that can carry currents in either direction as required to provide the assist.
摘要:
An MTJ memory cell and/or an array of such cells is provided wherein each such cell has a small circular horizontal cross-section of 1.0 microns or less in diameter and wherein the ferromagnetic free layer of each such cell has a magnetic anisotropy produced by a magnetic coupling with a thin antiferromagnetic layer that is formed on the free layer. The MTJ memory cell so provided is far less sensitive to shape irregularities and edge defects than cells of the prior art.