Pattern fortification for HDD bit patterned media pattern transfer

Abstract

A method and apparatus for forming a magnetic layer having a pattern of magnetic properties on a substrate is described. The method includes using a metal nitride hardmask layer to pattern the magnetic layer by plasma exposure. The metal nitride layer is patterned using a nanoimprint patterning process with a silicon oxide pattern negative material. The pattern is developed in the metal nitride using a halogen and oxygen containing remote plasma, and is removed after plasma exposure using a caustic wet strip process. All processing is done at low temperatures to avoid thermal damage to magnetic materials.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims benefit of U.S. Provisional Patent Application Ser. No. 61 / 726,234 filed Nov. 14, 2012, which is incorporated herein by reference.FIELD[0002]Embodiments described herein generally relate to methods and apparatus for producing magnetic media. More specifically, embodiments described herein relate to methods and apparatus for creating a pattern of magnetic properties in a magnetically active surface.BACKGROUND[0003]Magnetic media are important information storage devices, prominent examples of which are hard disk drives and magnetic memory devices such as MRAM. Magnetic media are generally characterized by a surface with an addressable pattern of magnetic properties that enable localized alteration of a detectable property of the surface. Typically, domains of magnetically active material are separated by domains of magnetically inactive material, so that a magnetic property of one domain, such as residual magnetism,...

AI Technical Summary

Benefits of technology

This patent describes a method and apparatus for creating a patterned magnetic surface on a substrate. A metal nitride film is deposited on the substrate and then patterned to form protected domains and unprotected domains of the substrate surface. The unprotected domains are then treated with a plasma to alter their magnetic properties, and the metal nitride film is removed to create the patterned surface with the desired magnetic properties. The method and apparatus can be used in various manufacturing processes and can be adapted for different substrates and magnetic properties.

Problems solved by technology

Such trends create challenges in maintaining separation and addressability of the domains.

For example, as magnetic domains grow smaller and closer together, maintaining a detectable separation of the magnetic fields present in the domains becomes more difficult.

In many cases the processes used to alter the magnetic properties of the substrate involve plasma implantation, which may degrade soft masking materials, altering the pattern formed therein.

The hardmask is not perfect, however.

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