摘要:
The present invention provides a novel high magnetic moment material for the pole pieces as well as a metal-in-gap configuration for the pole tips of either an inductive magnetic head only or the inductive portion of a MR head. The novel material is Ni.sub.45 Fe.sub.55. In the MIG configuration each pole piece of the inductive head or the inductive head portion of a MR head has a combination of layers, each combination of layers including a first layer of high magnetic moment material Ni.sub.45 Fe.sub.55 adjacent to a transducing gap and a second layer of low magnetic moment material such as Permalloy (Ni.sub.81 Fe.sub.19) further away from the gap. Since both layers are made of NiFe all the desirable properties of this type of material can be employed as well as simplifying its construction with similar plating baths. The saturation of the first layers is 50 to 60 percent higher than the saturation of the second layers. The present invention avoids effects of magnetostriction in spite of the high magnetic moment of the first layers. By appropriately selecting the thickness ratio of the second layer with respect to the first layer the magnetostriction of the laminated structure can be reduced substantially to zero. When this thickness ratio is in the order of five to nine the magnetostriction is reduced to, or slightly below, zero. If the inductive head is employed for write functions only then the second pole tip or both pole tips can be constructed of the high moment Ni.sub.45 Fe.sub.55 material without any thickness ratio or MIG configuration constraints.
摘要:
A thin film magnetic write head is provided with a notch structure located on top of one of two pole layers. The notch structure is a generally U-shaped thin film layer which forms a trench inside the U for the containment of one or more pole tip layers in the pole tip region of the head. The notch structure has front surfaces at the tips of the legs of the U which lie in a plane that forms a part of the air bearing surface. The thickness of the notch layer is substantially equal to the thickness or thicknesses of the one or more pole tip layers located in the trench. A method of manufacturing the write head includes forming a very thin photoresist layer for defining the notch structure. The notch structure is well-defined which in turn allows the one or more pole tip layers to be well-defined with a very narrow trackwidth in the trench.
摘要:
The present invention provides a novel high magnetic moment material for the pole pieces as well as a metal-in-gap configuration for the pole tips of either an inductive magnetic head only or the inductive portion of a MR head. The novel material is Ni.sub.45 Fe.sub.55. In the MIG configuration each pole piece of the inductive head or the inductive head portion of a MR head has a combination of layers, each combination of layers including a first layer of high magnetic moment material Ni.sub.45 Fe.sub.55 adjacent to a transducing gap and a second layer of low magnetic moment material such as Permalloy (Ni.sub.81 Fe.sub.19) further away from the gap. Since both layers are made of NiFe all the desirable properties of this type of material can be employed as well as simplifying its construction with similar plating baths. The saturation of the first layers is 50 to 60 percent higher than the saturation of the second layers. The present invention avoids effects of magnetostriction in spite of the high magnetic moment of the first layers. By appropriately selecting the thickness ratio of the second layer with respect to the first layer the magnetostriction of the laminated structure can be reduced substantially to zero. When this thickness ratio is in the order of five to nine the magnetostriction is reduced to, or slightly below, zero. If the inductive head is employed for write functions only then the second pole tip or both pole tips can be constructed of the high moment Ni.sub.45 Fe.sub.55 material without any thickness ratio or MIG configuration constraints.
摘要:
A method is provided for making a thin film magnetic write head with a notch structure located on top of one of two pole layers. The notch structure is a generally U-shaped thin film layer which forms a trench inside the U for the containment of one or more pole tip layers in the pole tip region of the head. The notch structure has front surfaces at the tips of the legs of the U which lie in a plane that forms a part of the air bearing surface. The thickness of the notch layer is substantially equal to the thickness or thicknesses of the one or more pole tip layers located in the trench. A method of manufacturing the write head includes forming a very thin photoresist layer for defining the notch structure. The notch structure is well-defined which in turn allows the one or more pole tip layers to be well-defined with a very narrow trackwidth in the trench.
摘要:
An MRAM structure is disclosed in which the bottom electrode has an amorphous TaN capping layer to consistently provide smooth and dense growth for AFM, pinned, tunnel barrier, and free layers in an overlying MTJ. Unlike a conventional Ta capping layer, TaN is oxidation resistant and has high resistivity to avoid shunting of a sense current caused by redeposition of the capping layer on the sidewalls of the tunnel barrier layer. Alternatively, the α-TaN layer is the seed layer in the MTJ. Furthermore, the seed layer may be a composite layer comprised of a NiCr, NiFe, or NiFeCr layer on the α-TaN layer. An α-TaN capping layer or seed layer can also be used in a TMR read head. An MTJ formed on an α-TaN capping layer has a high MR ratio, high Vb, and a RA similar to results obtained from MTJs based on an optimized Ta capping layer.
摘要:
Methods are presented for fabricating an MTJ element having a precisely controlled spacing between its free layer and a bit line and, in addition, having a protective spacer layer formed abutting the lateral sides of the MTJ element to eliminate leakage currents between MTJ layers and the bit line. Each method forms a dielectric spacer layer on the lateral sides of the MTJ element and, depending on the method, includes an additional layer that protects the spacer layer during etching processes used to form a Cu damascene bit line. At various stages in the process, a dielectric layer is also formed to act as a CMP stop layer so that the capping layer on the MTJ element is not thinned by the CMP process that planarizes the surrounding insulation. Subsequent to planarization, the stop layer is removed by an anisotropic etch of such precision that the MTJ element capping layer is not thinned and serves to maintain an exact spacing between the bit line and the MTJ free layer.
摘要:
One of the major requirements for higher frequency extendability is to reduce yoke length and inductance in order to have fast saturation. This has been accomplished by using a design that provides a cavity in the lower pole piece inside which is located at least two coils, one on top of the other. A process for manufacturing the device is also described.
摘要:
Aggressive (i.e. tight tolerance) stitching offers several advantages for magnetic write heads but at the cost of some losses during pole trimming. This problem has been overcome by replacing the alumina filler layer, that is used to protect the stitched pole during trimming, with a layer of electro-plated material. Because of the superior step coverage associated with the plating method of deposition, pole trimming can then proceed without the introduction of stresses to the stitched pole while it is being trimmed.
摘要:
A method for forming an abutted junction GMR bottom spin valve sensor in which the free layer has a maximum effective length due to the elimination or minimization of bias layer and conducting lead layer overspreading onto the sensor element and the consequent reduction of current shunting. The overspreading is eliminated by forming a thin dielectric layer on the upper surface of the sensor element. When the biasing and conducting leads are formed on the abutted junction, they overspread onto this layer and the overspread can be removed by an ion-milling process during which the dielectric layer protects the sensor.
摘要:
Present processes used for planarizing a cavity filled with a coil and hard baked photoresist require that a significant amount of the thickness of the coils be removed. This increases the DC resistance of the coil. In the present invention, CMP is terminated as soon as the coils are exposed, allowing their full thickness to be retained and resulting in minimum DC resistance. Application of this process to the manufacture of a planar magnetic write head is described.