Pmr write head with assisted magnetic layer

Abstract

A PMR writer is disclosed wherein a magnetic assist layer (MAL) made of an anisotropic (−Ku) or (+Ku) magnetic material is formed along a main pole trailing side to optimize the vertical magnetic field and field gradient at the air bearing surface. A Ru seed layer is formed between the main pole and (−Ku) MAL to induce a hard axis direction toward the main pole. A (−Ku) MAL is preferably comprised of hcp-CoIr while CoPt and FePt are examples of a (+Ku) MAL. The MAL has a down-track thickness from 5 to 20 nm, a width equal to the track width in a cross-track direction, and extends 100 to 500 nm in a direction toward a back end of the main pole. As a result, flux leakage from the main pole to trailing shield is reduced and aerial density is increased. A method for fabricating the PMR writer is provided.

Description

RELATED PATENT APPLICATION[0001]This application is related to the following: Docket # HT10-031, Ser. No. ______; filing date ______; assigned to a common assignee, and herein incorporated by reference in its entirety.FIELD OF THE INVENTION[0002]The invention relates to a thin magnetic film with an anisotropic magnetic property that is added to the trailing side of a main pole and thereby provides additional magnetic charge on the ABS surface to improve writability and field gradient.BACKGROUND OF THE INVENTION[0003]In today's perpendicular magnetic recording (PMR) technology, an all wrapped around (AWA) shield writer is widely used by the major hard disk drive (HDD) manufacturers. The function of a trailing shield in an AWA structure is to improve the magnetic field gradient along a down track direction which is a key requirement for high bits per inch (BPI). Meanwhile, side shields and a leading shield serve to define a narrower writer bubble which is important for realizing highe...

AI Technical Summary

Benefits of technology

The magnetic assist layer significantly reduces flux leakage from the main pole to the trailing shield, enabling a thinner write gap and improving both write field amplitude and field gradient, thus enhancing bits per inch (BPI) and tracks per inch (TPI) in PMR writer designs.

Problems solved by technology

Therefore, narrowing the gap between a shield and main pole will only lead to an unwanted flux path from the main pole to the shield which in turn reduces the writability (magnetic field) of the writer on magnetic recording media.

This dilemma is considered one of the most significant challenges to improving current writer designs and performance.

With the constraint of write field amplitude on the magnetic medium 10, further reduction of the gap between main pole and shields is not productive which limits achieving a higher recording area density.

However, current technology does not enable further field gradient improvement when the write gap shrinks below 20 nm.

However, the stacked layers are recessed from the ABS and are not expected to entirely prevent flux leakage from the main pole to an adjacent trailing shield.

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