Headway Technologies, Incorporated

Jas Chudasama

Chao-Peng Chen

Chien-Li Lin

David K Wagner

Situan Lam

Chih-I Yang

William Stokes

Chao-Peng Cheng

A method of removing copper oxide from copper surfaces is disclosed that comprises application of vapor generated by an ultrasonic wave nebulizer. The energized vapor droplets include water and a weak organic acid such as acetic acid, lactic acid, citric acid, uric acid, oxalic acid, or formic acid that have a vapor pressure proximate to that of water. The weak organic acid preferably has a pKa high enough to avoid Cu etching but is sufficiently acidic to remove copper oxide at a rate that is compatible with high throughput manufacturing. In one embodiment, weak acid/water vapor is applied to a substrate in a spin bowl and is followed by a deionized water rinse step in the same spin bowl. Improved wettability results in improved uniformity in subsequently plated copper films. Considerable cost savings is realized as a result of reduced chemical consumption and higher product yields.

Copper plating method

A method of activating a copper seed layer during a plating process is disclosed that comprises application of vapor generated by an ultrasonic wave nebulizer. The energized vapor droplets include water and a weak organic acid such as acetic acid, lactic acid, citric acid, uric acid, oxalic acid, or formic acid that have a vapor pressure proximate to that of water. The weak organic acid preferably has a pKa high enough to avoid Cu etching but is sufficiently acidic to remove copper oxide at a rate that is compatible with high throughput manufacturing. In one embodiment, weak acid/water vapor is applied to a substrate in a spin bowl and is followed by a deionized water rinse step in the same spin bowl. Improved wettability results in improved uniformity in subsequently plated copper films. Considerable cost savings is realized as a result of reduced chemical consumption and higher product yields.

A method of removing an alumina layer around a main pole layer during perpendicular magnetic recording head fabrication is disclosed. The alumina etch sequence includes immersing a substrate in a series of aqueous solutions purged with an inert gas to remove oxygen thereby avoiding corrosion of the main pole. Initially, the substrate is soaked and heated in deionized (DI) water. Once heated, the substrate is immersed in an etching bath at about 80&#xb0; C. and pH 10.5. Bath chemistry is preferably based on NaCOand NaHCO, and Npurging improves etch uniformity and reduces residue. Thereafter, the substrate is rinsed in a second DI water bath between room temperature and 80&#xb0; C., and finally subjected to a quick dump rinse before drying. Inert gas, preferably N, may be introduced into the aqueous solutions through a purge board having a plurality of openings and positioned proximate to the bottom of a bath container.

Method of reducing main pole corrosion during aluminum oxide etch

A method of forming a write pole in a PMR head is disclosed that involves forming an opening in a mold forming layer. A conformal Ru seed layer is formed within the opening and on a top surface. An auxiliary layer made of CoFeNi or alloys thereof is formed as a conformal layer on the seed layer. All or part of the auxiliary layer is removed in an electroplating solution by applying a (&#x2212;) current or voltage during an activation step that is controlled by activation time. Thereafter, a magnetic material is electroplated with a (+) current to fill the opening and preferably has the same CoFeNi composition as the auxiliary layer. The method avoids Ru oxidation that causes poor adhesion to CoFeNi, and elevated surfactant levels that lead to write pole impurities. Voids in the plated material are significantly reduced by forming a seed layer surface with improved wettability.

Method to reduce void formation during trapezoidal write pole plating in perpendicular recording

A process for cathodically reducing unwanted Feions to needed Feions in an acidic ferrous based plating bath without reducing agents is disclosed. An auxiliary potential of 0.1 to 0.3 volts vs. SCE is applied between the working electrode and a reference electrode and can reduce the molar ratio [Fe]/[Fe] to 1 ppm without depositing Fe or other metals on the working electrode or causing hydrogen evolution. The process is applicable to electroplating soft magnetic films such as NiFe, FeCo, and CoNiFe and can be performed during plating or during cell idling. The process is cost effective by reducing the amount of hazardous waste and tool down time due to routine solution swap. Other benefits are improved uniformity in composition and thickness of plated films because issues associated with decomposed reducing agents are avoided.

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Milpitas, CA, United States of America

Jas Chudasama