Magnetic Disk of a Data Storage Device with Tempered Growth of Magnetic Recording Layer

Patent metadata

Field	Value
Publication number	US-2016372146-A1
Application number	US-201415032963-A
Country	US
Kind code	A1
Filing date	Oct 31, 2014
Priority date	Nov 1, 2013
Publication date	Dec 22, 2016
Grant date	—

Abstract

In one aspect, a magnetic data storage device comprises a template layer, an underlayer, and a magnetic recording layer. The template layer includes a patterned array of protruding features. The underlayer is formed on the patterned array of protruding features of the template layer. The underlayer includes an array pattern of protruding features that aligns with the patterned array of protruding features of the template layer. The magnetic recording layer is formed on the underlayer. The magnetic recording layer includes columnar grains of magnetic material separated by grain boundaries of non-magnetic material, with each columnar grain being on a protruding feature of the array pattern of the underlayer, and the grain boundaries being in trenches between the protruding features of the array pattern of the underlayer.

First claim

What is claimed is:

1 . A magnetic disk of a data storage device, the magnetic disk comprising:
a template layer with a patterned array of protruding features; an underlayer formed on the patterned array of protruding features of the template layer, the underlayer having an array pattern of protruding features that aligns with the patterned array of protruding features of the template layer; and a magnetic recording layer formed on the underlayer, the magnetic recording layer comprising columnar grains of magnetic material separated by grain boundaries of non-magnetic material, with each columnar grain being on a protruding feature of the array pattern of the underlayer, and the grain boundaries being in trenches between the protruding features of the array pattern of the underlayer.

2 . The magnetic disk of claim 1 , further comprising:
a substrate comprising a single-crystal silicon wafer, a wafer with one or more oxide layers, an aluminum substrate, or a glass substrate; and an adhesion layer deposited on the substrate; wherein the template layer is formed on the adhesion layer.

3 . The magnetic disk of claim 1 , further comprising:
a substrate comprising a single-crystal silicon wafer, a wafer with one or more oxide layers, an aluminum substrate, or a glass substrate; a second underlayer formed on the substrate; a non-magnetic exchange break layer formed on the second underlayer; and one or more intermediate layers formed on the non-magnetic exchange break layer, the one or more intermediate layers configured to manage heat flow through the magnetic storage device; wherein the template layer is formed on the one or more intermediate layers.

4 . The magnetic disk of claim 1 , wherein the template layer has a crystalline orientation that matches a lattice orientation of the underlayer, and the template layer comprises one or more of platinum, nickel, tungsten, magnesium, oxygen, ruthenium, aluminum, titanium, or molybdenum.

5 . The magnetic disk of claim 1 , wherein the patterned array is fabricated using self-assembled nanostructures to define positions of the dome-shaped features, and wherein the self-assembled nanostructures comprise a copolymer of a block copolymer, the block copolymer comprising poly(styrene-block-dimethyl siloxane), poly(styrene-block-methyl methacrylate), poly(styrene-block-isoprene), poly(styrene-block-vinyl pyridine), poly(styrene-block-ferrocenyl dimethylsilane), poly(ethylene oxide-block-isoprene), poly(ethylene oxide-block-butadiene), or poly(ethylene oxide-block-styrene).

6 . The magnetic disk of claim 1 , wherein the patterned array is fabricated using self-assembled nanoparticles or nanoimprint lithography.

7 . The magnetic disk of claim 1 , wherein the underlayer comprises one or more of ruthenium, magnesium oxide, aluminum, titanium carbide, tungsten, titanium nitride, or molybdenum.

8 . The magnetic disk of claim 1 , wherein the magnetic material comprises one or more of cobalt, chromium, platinum, iron, palladium, manganese, aluminum, or nickel, and the non-magnetic material comprises silicon oxide, tantalum oxide, titanium oxide, yttrium oxide, carbon, or boron.

9 . The magnetic disk of claim 1 , wherein the patterned array of protruding features comprises a patterned array of dome-shaped features, cone-shaped features, or a combination of dome-shape features and cone-shaped features.

10 . The magnetic disk of claim 1 , wherein the columnar grains have a pitch of 35 nanometers or less.

11 . The magnetic storage device of claim 1 , wherein the magnetic recording layer has a thickness between 5 nanometers and 15 nanometers.

12 . A method for fabricating a magnetic disk of a data storage device, the method comprising:
providing a template layer; transferring an array pattern of self-assembled nanostructures into the template layer to form a patterned array of protruding features in the template layer, with the template layer retaining the patterned array of protruding features during fabrication of other layers of the magnetic disk; depositing, onto the patterned array of protruding features of the template layer, an underlayer to have an array pattern of protruding features that aligns with the patterned array of protruding features of the template layer; and depositing, onto the underlayer, a magnetic recording layer to grow columnar grains of magnetic material on the protruding features of the array pattern of the underlayer and grain boundaries of non-magnetic material in trenches between the protruding features of the array pattern of the underlayer.

13 . The method of claim 12 , further comprising:
providing a substrate; depositing, onto the substrate, an adhesion layer; and depositing, onto the adhesion layer, at least 5 nanometers of one or more of platinum, nickel, tungsten magnesium oxide, ruthenium, aluminum, titanium, or molybdenum to form the template layer.

14 . The method of claim 12 , further comprising:
providing a substrate; depositing, onto the substrate or an adhesion layer on the substrate, a second underlayer; depositing, onto the second underlayer, an non-magnetic exchange break layer; and depositing, onto the non-magnetic exchange break layer, at least 5 nanometers of one or more of platinum, nickel, tungsten magnesium oxide, ruthenium, aluminum, titanium, or molybdenum to form the template layer.

15 . The method of claim 12 , wherein transferring the array pattern of self-assembled nanostructures into the template layer comprises:
depositing, onto the template layer, a mask layer comprising one or more of carbon, silicon, silicon nitride, or tungsten; depositing, onto the mask layer, a block copolymer layer comprising a block copolymer dissolved in a solution, the solution comprising one or more of toluene, acetone, chlorohexane, or propylene glycol monomethyl ether acetate, and the block copolymer comprising poly(styrene-block-dimethyl siloxane), poly(styrene-block-methyl methacrylate), poly(styrene-block-isoprene), poly(styrene-block-vinyl pyridine), poly(styrene-block-ferrocenyl dimethylsilane), poly(ethylene oxide-block-isoprene), poly(ethylene oxide-block-butadiene), or poly(ethylene oxide-block-styrene), with one block of the block copolymer being nanostructures that self-assemble into the array pattern; treating the block copolymer to direct self-assembly of the nanostructures into the array pattern and to stabilize positions of the self-assembled nanostructures on the mask layer; etching the block copolymer layer to expose portions of the mask layer while retaining the self-assembled nanostructures; etching the exposed portions of the mask layer to transfer the array pattern of the self-assembled nanostructures into the mask layer to form a patterned array of pillars in the mask layer; removing the self-assembled nanostructures of the block copolymer layer; milling the template layer to transfer the patterned array of pillars into the template layer to form the patterned array of protruding features in the template layer; and removing remaining portions of the mask layer.

16 . The method of claim 15 , wherein treating the block copolymer layer comprises:
directing micro-phase separation or ordering of the block copolymer, with the nanostructures self-assembling into the array pattern, with each nanostructure of the array pattern comprising one of a sphere or a cylinder positioned in a matrix of another block of the block copolymer, with the array pattern having a pitch less than 35 nanometers.

17 . The method of claim 15 , wherein treat

Assignees

• Univ Carnegie Mellon

Inventors

• Sundar Vignesh
• Zhu Jian-Gang
• Laughlin David E

Classifications

• G11B5/746

  Bit Patterned record carriers, wherein each magnetic isolated data island corresponds to a bit · CPC title

• G11B5/743

  Patterned record carriers, wherein the magnetic recording layer is patterned into magnetic isolated data islands, e.g. discrete tracks · CPC title

• G11B5/66

  the record carriers consisting of several layers · CPC title

• G11B5/73921

  Glass or ceramic substrates · CPC title

• G11B5/73911

  Inorganic substrates · CPC title