Method for making a perpendicular thermally-assisted recording (TAR) magnetic recording disk having a carbon segregant

Abstract

A method of making a thermally-assisted recording (TAR) disk includes etching an initial layer of generally spherically shaped FePt grains encapsulated by shells of graphitic carbon layers. The etching partially or completely removes the carbon layers on the tops of the shells, exposing the FePt grains while leaving carbon segregant material between the FePt grains. Additional Fe, Pt and C are then simultaneously deposited. The additional Fe and Pt grow on the exposed FePt grains and increase the vertical height of the grains, resulting in growth of columnar FePt grains. The additional C forms on top of the grains that together with the intergranular carbon form larger carbon shells. The resulting FePt grains thus have a generally columnar shape with perpendicular magnetic anisotropy, rather than a generally spherical shape. Lateral grain isolation is maintained by the carbon segregant remaining between the grains.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates generally to perpendicular magnetic recording media for use as thermally-assisted recording (TAR) media, and more particularly to a method for making a TAR disk wherein the magnetic recording layer includes a carbon segregant.[0003]2. Description of the Related Art[0004]In conventional continuous magnetic recording media, the magnetic recording layer is a continuous layer over the entire surface of the disk. In magnetic recording disk drives the magnetic material (or media) for the recording layer on the disk is chosen to have sufficient coercivity such that the magnetized data regions that define the data “bits” are written precisely and retain their magnetization state until written over by new data bits. As the areal data density (the number of bits that can be recorded on a unit surface area of the disk) increases, the magnetic grains that make up the data bits can be so small that they can be...

AI Technical Summary

Benefits of technology

This patent is for a method to make a TAR disk, which is a type of memory device. The method involves creating a layer of FePt grains, which are encapsulated by shells of graphitic carbon layers. An etching step is then performed to remove some of the carbon layers on the top of the shells, which encourages the growth of columnar FePt grains. This results in a structure with perpendicular magnetic anisotropy and larger carbon shells. The method maintains lateral grain isolation through the carbon segregant between the grains. Additionally, the method allows for the growth of taller grains with a columnar shape and the co-deposition of additional Fe and Pt to form shells over the grains and as intergranular segregant material between the columnar grains. Overall, this method produces a highly organized and efficient TAR disk with improved performance.

Problems solved by technology

However, increasing Ku also increases the coercivity of the media, which can exceed the write field capability of the write head.

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