Structures and methods for templated growth of high areal density heat assisted magnetic recording media

Patent metadata

Field	Value
Publication number	US-10347281-B2
Application number	US-201514728871-A
Country	US
Kind code	B2
Filing date	Jun 2, 2015
Priority date	Jun 2, 2015
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

Methods are disclosed for increasing areal density in Heat Assisted Magnetic Recording (HAMR) data storage systems by controlling the media layer grain size, grain size distribution, and pitch via templating techniques that are compatible with the high temperature HAMR media deposition. Embodiments include using current HAMR media seed layers as well as additionally introduced interlayers for the templating process. Topographic as well as chemical templating methods are disclosed that may employ nanoimprint technology or nanoparticle self-assembly among other patterning techniques.

First claim

The invention claimed is:

1. A method for generating high areal density heat assisted magnetic recording (HAMR) media using templated growth on a substrate, the method comprising the steps of:
depositing an underlayer stack, wherein the underlayer stack comprises at least a pattern layer;
patterning the pattern layer in the underlayer stack to form a patterned seed layer comprising pillars; and
depositing HAMR magnetic material at high temperatures ranging from 300 to 700° C. onto the patterned seed layer to form a tightly distributed magnetic grain structure having a magnetic grain diametric distribution below 15% of a mean diameter, and wherein the deposition process for the magnetic material is shadowed to inhibit deposition of magnetic material-between the pillars;
wherein the underlayer stack comprises one or more of the following materials: (002) magnesium oxide, (002) titanium nitride, both (002) magnesium oxide and (002) titanium nitride, and/or single layers or combinations of materials including (002) strontium titanium-oxide, (002) magnesium titanium-oxide, and/or (002) magnesium oxide-silicon oxide.

2. The method of claim 1 , wherein the underlayer stack ranges from 1 to 70 nm in thickness and is deposited at a temperature ranging from room temperature to 300° C.

3. The method of claim 1 , wherein the step of patterning the pattern layer in the underlayer stack to form the patterned seed layer comprises the steps of:
depositing a resist layer;
patterning the resist layer; and
transferring the pattern in the resist layer to the pattern layer in the underlayer stack, thereby patterning the pattern layer in the underlayer stack into a patterned seed layer.

4. The method of claim 3 , wherein the step of patterning the resist layer comprises imprint lithography.

5. The method of claim 1 , wherein the step of patterning the pattern layer in the underlayer stack to form the patterned seed layer comprises the steps of:
depositing a nanoparticle array layer; and
transferring the pattern in the nanoparticle array layer to the pattern layer in the underlayer stack, thereby patterning the pattern layer in the underlayer stack into a patterned seed layer.

6. A method for generating high areal density heat assisted magnetic recording (HAMR) media using templated growth on a substrate, the method comprising the steps of:
depositing an underlayer stack, wherein the underlayer stack comprises at least a pattern layer;
depositing a metal layer onto the pattern layer in the underlayer stack at temperatures above 300° C.;
patterning the metal layer to form a patterned metal seed layer comprising pillars; and
depositing HAMR magnetic material at high temperatures ranging from 300 to 700° C. onto the patterned metal seed layer to form a tightly distributed diametric magnetic grain structure, and wherein the deposition process for the magnetic material is shadowed to inhibit deposition of magnetic material between the pillars.

7. The method of claim 6 , wherein the underlayer stack comprises one or more of the following materials: (002) magnesium oxide, (002) titanium nitride, both (002) magnesium oxide and (002) titanium nitride, and/or combinations of materials including (002) strontium titanium-oxide, (002) magnesium titanium-oxide, and/or (002) magnesium oxide-silicon oxide.

8. The method of claim 7 , wherein the underlayer stack ranges from 1 to 70 nm in thickness and is deposited at a temperature ranging from room temperature to 300° C.

9. The method of claim 6 , wherein the step of patterning the metal layer to form the patterned metal seed layer comprises the steps of:
depositing a resist layer;
patterning the resist layer; and
transferring the pattern in the resist layer to the metal layer, thereby patterning the metal layer into a patterned metal seed layer.

10. The method of claim 9 , wherein the step of patterning the resist layer comprises imprint lithography.

11. The method of claim 6 , wherein the step of patterning the metal layer to form the patterned metal seed layer comprises the steps of:
depositing a nanoparticle array layer; and
transferring the pattern in the nanoparticle array layer to the metal layer, thereby patterning the metal layer into a patterned metal seed layer.

12. The method of claim 6 , wherein the step of depositing the metal layer comprises the steps of:
an optional first step depositing an underlayer of (002)-oriented CrRu, RuAl, CrA, and/or RuA alloys (where A is another metal); and
a second step depositing one or more metal layers of (002)-oriented Pt, Pd, Ir, Rh, Os, or FePt, wherein each metal layer of the one or more metal layers comprises one or more of these metals;
wherein the metal layer deposition is performed at elevated temperatures of at least 300° C.

13. The method of claim 12 , wherein the metal layer ranges from 1 to 10 nm in thickness.

14. A method for generating high areal density heat assisted magnetic recording (HAMR) media using hole-tone templated growth on a substrate, the method comprising the steps of:
depositing an underlayer stack, wherein the underlayer stack comprises at least a pattern layer;
optionally depositing a metal layer at temperatures above 300° C. onto the pattern layer in the underlayer stack;
depositing a template material layer onto the pattern layer of the underlayer stack or onto the optional metal layer;
patterning the template material layer to form a hole-tone template;
depositing HAMR magnetic material at high temperatures ranging from 300 to 700° C. onto the template layer to form a tightly distributed diametric magnetic grain structure having a magnetic grain diametric distribution below 15% of a mean diameter, and the dimensions of holes in the hole-tone template determine the sizes and shapes of the magnetic grains; and
removing the hole-tone template.

15. The method of claim 14 , wherein the underlayer stack comprises one or more of the following materials: (002) magnesium oxide, (002) titanium nitride, both (002) magnesium oxide and (002) titanium nitride, and/or single layers or combinations of materials including (002) strontium titanium-oxide, (002) magnesium titanium-oxide, and/or (002) magnesium oxide-silicon oxide.

16. The method of claim 15 , wherein the underlayer stack ranges from 1 to 70 nm in thickness and is deposited at a temperature ranging from room temperature to 300° C.

17. The method of claim 14 , wherein the step of patterning the template material layer to form the hole-tone template comprises the steps of:
depositing a resist layer;
patterning the resist layer; and
transferring the pattern in the resist layer to the template material layer, thereby patterning the template material layer into a hole-tone template.

18. The method of claim 17 , wherein the step of patterning the resist layer comprises imprint lithography.

19. The method of claim 14 , wherein the step of patterning the template material layer to form the hole-tone template comprises the steps of:
depositing a nanoparticle array layer; and
transferring the pattern in the nanoparticle array layer to the template material layer, thereby patterning the template material layer into a hole-tone template.

20. The method of claim 14 , further comprising:
depositing the metal layer at temperatures above 300° C. onto the pattern layer in the underlayer stack, comprising the steps of:
an optional first step depositing an underlayer of (002)-oriented CrRu, RuAl, CrA, and/or RuA alloys, wherein A is another metal; and

Assignees

• HGST Netherlands BV
• Western Digital Tech Inc

Inventors

• Arora Hitesh
• Gurney Bruce
• Hellwig Olav
• IWATA Jodi Mari
• Santos Tiffany Suzanne
• Weller Dieter K
• ZHU Frank

Classifications

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title

• G11B5/746

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

• G11B5/855 Primary

  Coating only part of a support with a magnetic layer · CPC title