Abstract: A polymer coated cathode material not subject to catastrophic failure through local overheating comprises cathode active material particles and a polymer layer. The polymer layer wraps each cathode active material particle. The polymer coated cathode material has a core-shell structure. The core-shell structure comprises a core and a shell, the core is formed by the cathode active material particle, the shell is formed by the polymer layer. A battery made by the polymer coated cathode material is safer, in that when there is a short circuit, the short circuit only happens locally and a chain reaction is avoided. Only a part of the battery may reach high temperature, preventing an explosion of the battery. A cathode using the polymer coated cathode material, and a battery using the cathode are also provided.

Abstract: A battery having the electrodes of multiple battery cell types are interleaved to prevent thermal runaway by cooling a shorted region between electrodes. The electrodes of each of the battery cell types with a first polarity share a pair of the common electrodes having a second polarity. The electrodes of the multiple battery cell types and the multiple common electrodes are interleaved such that if the electrodes of the multiple battery cell types and the adjacent common electrodes of one or more battery cell types short together, the current within the shorted battery cells is sufficiently small to prevent thermal runaway and the electrodes of the adjacent cells of the other battery cell types of the first polarity and the common electrodes of the second polarity not having short circuits provide heat sinking for the heat generated by the short circuit to prevent thermal runaway.

Abstract: A battery having the electrodes of multiple battery cell types are interleaved to prevent thermal runaway by cooling a shorted region between electrodes. The electrodes of each of the battery cell types with a first polarity share a pair of the common electrodes having a second polarity. The electrodes of the multiple battery cell types and the multiple common electrodes are interleaved such that if the electrodes of the multiple battery cell types and the adjacent common electrodes of one or more battery cell types short together, the current within the shorted battery cells is sufficiently small to prevent thermal runaway and the electrodes of the adjacent cells of the other battery cell types of the first polarity and the common electrodes of the second polarity not having short circuits provide heat sinking for the heat generated by the short circuit to prevent thermal runaway.

Abstract: A battery having the electrodes of multiple cell types interleaved to prevent thermal runaway by cooling a shorted region between electrodes. The battery includes multiple cell types where each cell type has multiple electrodes a first polarity. The electrodes of each of the cell types share a pair of the common electrodes having a second polarity. The electrodes of the multiple cell types and the multiple common electrodes are interleaved such that if the electrodes of the multiple cell types and the adjacent common electrodes of one or more cell types short together, the current within the shorted cells is sufficiently small to prevent thermal runaway and the electrodes of the adjacent cells of the other cell types of the first polarity and the common electrodes of the second polarity not having short circuits provide heat sinking for the heat generated by the short circuit to prevent thermal runaway.

Abstract: A battery pack has series-parallel connected battery cells. An inrush current limiting circuit has current limiting devices and a current limiting tracking means limits inrush current from shorted battery cells. Each current limiting tracking means is coupled to the current limiting devices such that they limit an inrush current from parallel neighbor battery cells when one battery cell on the column shorts. The current limiting devices are variable buffer resistors with a positive temperature coefficient. The current limiting tracking means are heat sinks that thermally couples the buffer resistors together such that the buffer resistors increase in resistance with a temperature increase caused by current flowing through the buffer resistor associated with the shorted battery cell. Current regulating elements are in series with columns of battery cells for preventing inrush current to the columns of the battery cells.

Abstract: A battery having the electrodes of multiple cell types interleaved to prevent thermal runaway by cooling a shorted region between electrodes. The battery includes multiple cell types where each cell type has multiple electrodes a first polarity. The electrodes of each of the cell types share a pair of the common electrodes having a second polarity. The electrodes of the multiple cell types and the multiple common electrodes are interleaved such that if the electrodes of the multiple cell types and the adjacent common electrodes of one or more cell types short together, the current within the shorted cells is sufficiently small to prevent thermal runaway and the electrodes of the adjacent cells of the other cell types of the first polarity and the common electrodes of the second polarity not having short circuits provide heat sinking for the heat generated by the short circuit to prevent thermal runaway.

Abstract: A battery pack has series-parallel connected battery cells. An inrush current limiting circuit has current limiting devices and a current limiting tracking means limits inrush current from shorted battery cells. Each current limiting tracking means is coupled to the current limiting devices such that they limit an inrush current from parallel neighbor battery cells when one battery cell on the column shorts. The current limiting devices are variable buffer resistors with a positive temperature coefficient. The current limiting tracking means are heat sinks that thermally couples the buffer resistors together such that the buffer resistors increase in resistance with a temperature increase caused by current flowing through the buffer resistor associated with the shorted battery cell. Current regulating elements are in series with columns of battery cells for preventing inrush current to the columns of the battery cells.

Abstract: As the critical dimensions of liftoff patterns grow smaller, it becomes increasingly more difficult to make liftoff resists that have the required resolution. This problem has been overcome by use of a combination of ion beam processing and ozone slimming to form lift-off patterns with undercuts from a single layer of photoresist. The ion beam process serves to harden the top portion of the resist while the ozone is used to oxidize and erode the lower portion resist sidewall to form the undercut.

Abstract: A method for forming a bi-layer lift-off mask, including a hardened photoresistive stencil layer on a PMGI layer, for use in fabricating GMR read-head sensors with trackwidths of less than 0.1 microns and TMJ MRAM devices of similar critical dimensions. The stencil portion of the mask includes a narrow portion with sharply defined edge and corners which are formed, without rounding or extreme undercut, by a photolithographic process which includes the formation, in a first development process, of auxiliary pattern pieces over the corners of the stencil and a subsequent oxidation in ozone for removing those auxiliary pattern pieces and obtaining sharply defined edge and corners and a controlled dissolution of the PMGI layer.

Abstract: The problem of increased edge sensitivity associated with the reduction of the spacing between bias magnets in a CPP head has been solved by limiting the width of the bias cancellation layer and by adding an extra layer of insulation to ensure that current through the device flows only through its central area, thereby minimizing its edge reading sensitivity.

Abstract: A write pole for vertical magnetic recording is described. It includes a trapezoidal prism of high magnetic moment material, having inwardly sloping sidewalls. Its parallel surfaces are between about 0.1 and 0.3 microns apart and the sidewalls slope in the range of 15.5 to 60 degrees relative to vertical.

Abstract: The problem of increased edge sensitivity associated with the reduction of the spacing between bias magnets in a CPP head has been solved by limiting the width of the bias cancellation layer and by adding an extra layer of insulation to ensure that current through the device flows only through its central area, thereby minimizing its edge reading sensitivity.

Abstract: A “toggling” type of magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate with each memory stack having a plurality of toggle memory cells stacked along the Z axis. Each stack is located at an intersection region between the two orthogonal write lines. The cells are stacked in pairs, with the cells in each pair having their easy axes of magnetization aligned substantially parallel to one another and nonparallel with the X and Y axes. The cells in each pair have their free layers magnetically biased in opposite directions. Because the free layer of each cell in a pair is biased in a direction opposite to the bias direction of the free layer of the other cell, one cell in a pair can be toggle written without toggle writing the other cell in the pair. The bias fields on the free layers reduces the required switching field for each cell, which results in less write current and a lower-power toggling MRAM.

Abstract: A write pole for vertical magnetic recording is described. It includes a trapezoidal prism of high magnetic moment material, having inwardly sloping sidewalls. Its parallel surfaces are between about 0.1 and 0.3 microns apart and the sidewalls slope in the range of 15.5 to 60 degrees relative to vertical.

Abstract: A method for forming a big-layer lift-off mask for use in fabricating GMR read-head sensors with trackwidths of less than 0.1 microns. The mask layers are formed symmetrically on each other, each layer of the mask having a novel dog-bone shape and the lower mask layer being substantially undercut relative to the upper mask layer. The central portion of the lower mask layer forms a narrow ridge that maintains the upper mask layer at a fixed height above a substrate, thereby avoiding problems associated with big-layer lift-off masks of the prior art. The method of forming the lower ridge requires a carefully controlled undercutting of the lower mask layer, which is accomplished by using an ozone-assisted oxidation process.

Abstract: It is very difficult to produce a negative wall angle from either negative or positive-tone chemically amplified resists, especially by e-beam lithography. This problem has now been overcome by first forming a photoresist pedestal in the conventional way, followed by flood exposing with electrons. Then, a second development treatment is given. This results in removal of additional material from the sidewalls, said removal being greatest at the substrate and least at the pedestal's top surface, resulting in negatively sloping sidewalls. Application of this method to a process for forming a pole tip for a vertical magnetic writer is also discussed.

Abstract: We describe a family of magnetic read heads that each includes a GMR or MTJ stack. A part, no more than about 0.1 microns thick, has been removed from this stack a to form a pedestal having sidewalls comprising a vertical section that includes all of the free layer.

Abstract: Using a beam of xenon ions together with a suitable mask, a GMR stack is ion milled until a part of it, no more than about 0.1 microns thick, has been removed so that a pedestal, having sidewalls comprising a vertical section that includes all of the free layer, has been formed. This is followed by formation of the longitudinal bias and conductive lead layers in the usual way. Using xenon as the sputtering gas enables the point at which milling is terminated to be more precisely controlled.

Abstract: A magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate, with each memory stack having two memory cells stacked along the Z axis and each memory cell having an associated biasing layer. Each biasing layer reduces the switching field of its associated cell by applying a biasing field along the hard-axis of magnetization of the free layer of its associated cell. The free layers in the two cells in each stack have their in-plane easy axes of magnetization aligned parallel to one another. Each biasing layer has its in-plane magnetization direction oriented perpendicular to the easy axis of magnetization (and thus parallel to the hard axis) of the free layer in its associated cell. The hard-axis biasing fields generated by the two biasing layers are in opposite directions.

Abstract: A plated magnetic thin film of high saturation magnetization and low coercivity having the general form Co100-a-bFeaMb, where M can be Mo, Cr, W, Ni or Rh, which is suitable for use in magnetic recording heads that write on narrow trackwidth, high coercivity media. The plating method that produces the alloy includes four current application processes: direct current, pulsed current, pulse reversed current and conditioned pulse reversed current.