Headway Technologies, Incorporated

Tdk Corporation

Maglabs, Inc.

Amperex Technology Limited

Jei-Wei Chang

Kochan Ju

Cheng Tzong Horng

Mao-Min Chen

Simon H Liao

Youfeng Zheng

Chao-Peng Chen

Cherng-Chyi Han

Xuehua Wu

Yi-Chun Liu

Chyu-Jiuh Torng

Shou-Chen Kao

Hui-Chuan Wang

Rongfu Xiao

Li-Yan Zhu

Chunping Luo

Koichi Terunuma

Xiaohong Yang

Ru-Ying Tong

Po-Kang Wang

Yimin Guo

Bernard Dieny

Xizeng Shi

Chen-Jung Chien

Kevin K Lin

Yining Hu

Henry C Chang

Stuart Kao

Chun Liu

Rina Kaji

Si-Tuan Lam

Wensen Li

Xue Hua Wu

Min Li

Daisuke Miyauchi

Yue Liu

Yimin Hsu

Takahiko Machita

Kazumasa Yasuda

Rodney E Lee

Chaopeng Chen

Chao Chen

Jen-Wei C Koo

Cheng-Teh Wu

Arthur Hungshin Tao

Julie Chen

David Hernandez

Wen-Cherng Lau

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.

Merged battery cell with interleaved electrodes

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.

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.

Single layer resist liftoff process for nano track width

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.

Ozone-assisted lithography process with image enhancement for CPP head manufacturing

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.

Narrow track CPP head with bias cancellation

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.

Method to print photoresist lines with negative sidewalls

Process to manufacture narrow track CPP head with bias cancellation

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.

Magnetic random access memory with stacked toggle memory cells having oppositely-directed easy-axis biasing

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.

Ozone-assisted bi-layer lift-off stencil for narrow track CPP-GMR heads

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.

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.

Xenon ion beam to improve track width definition

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.

Magnetic random access memory with stacked memory cells having oppositely-directed hard-axis biasing

Currently, in a process of manufacturing a top spin valve structure, the shield-to-shield separation of a spin valve head cannot be below about 800 &#x212b;, mainly due to sensor-to-lead shorting problems. This problem has now been overcome by inserting a high permeability, high resistivity, thin film shield on the top or bottom (or both) sides of the spin valve sensor. A permeability greater than about 500 is required together with a resistivity about 5 times greater than that of the free layer and an MT value for the thin film shield that is 4 times greater than that of the free layer.

Method of manufacturing integrated spin valve head

Conventional liftoff processes used to define track width in magnetic read heads can produce an uneven etch-depth of dielectric materials around the sensor and cause shorting to the overlay top lead layer. This problem has been overcome by printing the images of track width and stripe height onto an intermediate layer to form a hard mask. Through this hard mask, the GMR stack can be selectively etched and then back-filled with a high-resistivity material by using newly developed electroless plating processes.

Method to form an embedded micro-pedestal in a conductive layer

Process of manufacturing a narrow track CCP head with bias cancellation

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Cupertino, CA, United States of America

Jei-Wei Chang