Headway Technologies, Incorporated

Situan Lam

Chao-Peng Chen

Jas Chudasama

Chien-Li Lin

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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Situan Lam