Method of manufacturing an ultra high saturation moment soft magnetic thin film
AssigneeHeadway Technologies, Inc.
InventorsChaopeng Chen, Kevin Lin, Jei Wei Chang
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Abstract
A method for forming 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 includes four current application processes: direct current, pulsed current, pulse reversed current and conditioned pulse reversed current.
Claims14
A method for forming a thin Co—Fe—M alloy plated magnetic film having an as-plated high saturation magnetic moment greater than 20 kG and low easy-axis coercivity of less than 13 Oe, comprising:
- providing a substrate to be plated;
- immersing said substrate in a paddle cell having a paddle speed of approximately 1 Hz and containing an electrolytic plating solution, said solution
- (a) having a pH in the approximate range between 2 and 4 and
- (b) including dissolved salts capable of providing a sufficient ionic concentration of Co ions, Fe ions and ions of the element M, and
- (c) including a supporting salt of sodium, potassium or ammonium chloride, sulfate, acetate, citrate, tartrate or sulfamate, and
- (d) including a chemical compound such as sodium saccharin to act as a stress relieving agent, and
- (d) including a pH buffering agent such as boric acid, and
- (d) further including a chemical compound such as sodium lauryl sulfate to act as a surfactant, and
- (e) being subjected to a magnetic field of approximately 1 kG;
- and
- employing a plating current which is a pulsed reversed current, a conditioned pulsed current or a combination of a pulsed reversed current and a conditioned pulsed current,
- wherein the pulsed reversed current includes anodic pulses during which an anodic current flows.
A method for forming a thin Co—Fe—Mo alloy plated magnetic film of thickness between 0.7 and 1.3 μm having a trace amount of MoOx and an as-plated high saturation magnetic moment greater than 20 kG and low coercivity, comprising:
- providing a substrate of AlTiC having an A2O3 undercoat and NiFe, CoNiFe, Cu, or Au sputtered underlayer of thickness between 0.07 and 0.1 μm.;
- immersing said substrate in a paddle cell having a paddle speed of approximately 1 Hz and containing an electrolytic plating solution, said solution
- (a) having a pH in the approximate range between 2 and 4 and
- (b) including 15-30 g/l of CoSo47H2O, and
- (c) including 8-50 g/l of FeSo47H2O, and
- (d) including 12-20 g/l of NH4Cl, and
- (d) including 20-35 g/l of H3BO3, and
- (d) including 0-0.5 g/l of NaMoO42H2O, and
- (e) including 0.5 g/l of C7H5NO3, and
- (f) including 0.1 g/l of C12H25NaO4S, and
- (e) being subjected to a magnetic field of approximately 1 kG;
- employing a plating current which is a pulsed reversed current consisting of a sequence, each element of said sequence comprising a cathodic pulse followed by an anodic pulse, wherein the cathodic pulse is of approximate magnitude 15 mA/cm2 and approximate 1 s duration and the anodic pulse is of approximate magnitude 15 mA/cm2 and of approximate duration of 10 ms.
Dependencies are inferred from the claim text.