Method of manufacturing a magnetic film having high coercivity for use as a hot seed in a magnetic write head

Patent metadata

Field	Value
Publication number	US-9805743-B2
Application number	US-201514712952-A
Country	US
Kind code	B2
Filing date	May 15, 2015
Priority date	Oct 14, 2012
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A method of forming a sub-structure, suitable for use as a hot seed in a perpendicular magnetic recording head, is described. A buffer layer of alumina with a thickness of 50-350 Angstroms is formed by atomic layer deposition as a write gap. Thereafter, one or more seed layers having a body-centered cubic (bcc) crystal structure may be deposited on the buffer layer. Finally, a magnetic film made of FeCo or FeNi with a coercivity of 60-110 Oe is deposited on the seed layer(s) by a physical vapor deposition (PVD) method at a rate of 0.48 to 3.6 Angstroms per second. The magnetic film is preferably annealed at 220° C. for 2 hours in a 250 Oe applied magnetic field.

First claim

We claim:

1. A process to form a magnetic film with a coercivity of sufficient magnitude for use as a hot seed in a magnetic recording writer having a write gap (WG), comprising:
(a) providing a substrate in a perpendicular magnetic recording writer;
(b) forming a buffer layer of Al 2 O 3 between 50 and 350 Angstroms thick on the substrate with an atomic layer deposition process;
(c) depositing the magnetic film on the buffer layer with a physical vapor deposition process at a deposition rate in a range of from 0.48 to 3.6 Angstroms per second wherein the magnetic film is selected from the group consisting of Fe 1-x Co x wherein x is about 20-55 atomic %, and Fe 1-y Ni y wherein y is about 5-55 atomic %; and
(d) annealing the magnetic film at a temperature from about 180° C. to 300° C. in an externally applied magnetic field ranging from 200 to 1000 Oe for at least 1.5 hours.

2. The process of claim 1 further comprising:
depositing one or more seed layers of nonmagnetic materials having a body-centered cubic (bcc) crystal structure on the Al 2 O 3 buffer layer prior to depositing the magnetic film.

3. The process of claim 2 wherein one or more of the seed layers is selected from a group consisting of Ta, W, TaW, Ti, V, Cr, Mn, Ni 1-v Cr v wherein v is from about 28-100 atomic %, and Cr 1-z Ti z wherein z is from 0 to about 37 atomic %.

4. The process of claim 2 wherein the substrate is the write gap.

5. The process of claim 4 wherein the Al 2 O 3 buffer layer is also part of the write gap.

6. The process of claim 4 wherein the one or more bcc seed layers constitute part of the write gap.

7. The process of claim 2 wherein the magnetic film has a coercivity greater than 70 Oe, as deposited, and a coercivity greater than 60 Oe after being magnetically annealed.

8. The process of claim 1 wherein the magnetic film has a coercivity greater than 60 Oe, as deposited, and a coercivity greater than 30 Oe, after being magnetically annealed.

Assignees

• Headway Tech Inc

Inventors

• Wang Shengyuan
• Zhang Kunliang
• Li Min

Classifications

• G11B5/1877

  including at least one magnetic thin film · CPC title

• C23C14/35

  by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} · CPC title

• G11B5/3116

  Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks (G11B5/3113, G11B5/245 take precedence) · CPC title

• C23C14/024

  Deposition of sublayers, e.g. to promote adhesion of the coating (C23C14/027 takes precedence) · CPC title

• Y10T29/49043

  Depositing magnetic layer or coating · CPC title