Evaluation of AlOx in Co/AlOx/Co spin tunneling junctions by XPS

Yuki Otaka; Hideo Kaiju; Mao Nishiyama; Naoki Sakaguchi; Kazuo Shiiki

doi:10.1557/proc-811-e3.7

Evaluation of AlO_x in Co/AlO_x/Co spin tunneling junctions by XPS

Yuki Otaka, Hideo Kaiju, Mao Nishiyama, Naoki Sakaguchi, Kazuo Shiiki

Department of Applied Physics and Physico-Informatics

Research output: Contribution to journal › Conference article › peer-review

3 Citations (Scopus)

Abstract

Oxidation states of AlO_x in Co/AlO_x/Co spin tunneling junctions were studied using X-ray photoelectron spectroscopy. Co(10nm)/AlO_x/Co(50nm) spin tunneling junctions were fabricated on glass substrates by ion-beam mask sputtering. The Al layers were deposited in various thicknesses and were oxidized in pure O₂ gas for 24-48 hours at room temperature. Co/AlO_x bilayers simultaneously fabricated were analyzed by XPS. The thicker the Al layer is deposited, the more the unoxidized Al remains. MR ratio of the junctions increased as the unoxidized Al decreased, and this result is qualitatively in agreement with the LMTO calculation result. The O/Al ratio of A1O_x layer is about 1.9-2.0, which means existence of the higher order oxides than Al₂O₃. XPS depth profiles showed that the unoxidized Al remains not only near the interface with Co but also near the surface when the deposited Al layer thickness is thick.

Original language	English
Pages (from-to)	431-436
Number of pages	6
Journal	Materials Research Society Symposium Proceedings
Volume	811
DOIs	https://doi.org/10.1557/proc-811-e3.7
Publication status	Published - 2004 Jan 1
Event	Integration of Advanced Micro- and Nanoelectronic Devices - Critical Issues and Solutions - San Francisco, CA, United States Duration: 2004 Apr 13 → 2004 Apr 16

ASJC Scopus subject areas

Materials Science(all)
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

Access to Document

10.1557/proc-811-e3.7

Cite this

@article{fbd23869af694377a8d408f8d4583b11,

title = "Evaluation of AlOx in Co/AlOx/Co spin tunneling junctions by XPS",

abstract = "Oxidation states of AlOx in Co/AlOx/Co spin tunneling junctions were studied using X-ray photoelectron spectroscopy. Co(10nm)/AlOx/Co(50nm) spin tunneling junctions were fabricated on glass substrates by ion-beam mask sputtering. The Al layers were deposited in various thicknesses and were oxidized in pure O2 gas for 24-48 hours at room temperature. Co/AlOx bilayers simultaneously fabricated were analyzed by XPS. The thicker the Al layer is deposited, the more the unoxidized Al remains. MR ratio of the junctions increased as the unoxidized Al decreased, and this result is qualitatively in agreement with the LMTO calculation result. The O/Al ratio of A1Ox layer is about 1.9-2.0, which means existence of the higher order oxides than Al2O3. XPS depth profiles showed that the unoxidized Al remains not only near the interface with Co but also near the surface when the deposited Al layer thickness is thick.",

author = "Yuki Otaka and Hideo Kaiju and Mao Nishiyama and Naoki Sakaguchi and Kazuo Shiiki",

year = "2004",

month = jan,

day = "1",

doi = "10.1557/proc-811-e3.7",

language = "English",

volume = "811",

pages = "431--436",

journal = "Materials Research Society Symposium Proceedings",

issn = "0272-9172",

publisher = "Materials Research Society",

note = "Integration of Advanced Micro- and Nanoelectronic Devices - Critical Issues and Solutions ; Conference date: 13-04-2004 Through 16-04-2004",

}

TY - JOUR

T1 - Evaluation of AlOx in Co/AlOx/Co spin tunneling junctions by XPS

AU - Otaka, Yuki

AU - Kaiju, Hideo

AU - Nishiyama, Mao

AU - Sakaguchi, Naoki

AU - Shiiki, Kazuo

PY - 2004/1/1

Y1 - 2004/1/1

N2 - Oxidation states of AlOx in Co/AlOx/Co spin tunneling junctions were studied using X-ray photoelectron spectroscopy. Co(10nm)/AlOx/Co(50nm) spin tunneling junctions were fabricated on glass substrates by ion-beam mask sputtering. The Al layers were deposited in various thicknesses and were oxidized in pure O2 gas for 24-48 hours at room temperature. Co/AlOx bilayers simultaneously fabricated were analyzed by XPS. The thicker the Al layer is deposited, the more the unoxidized Al remains. MR ratio of the junctions increased as the unoxidized Al decreased, and this result is qualitatively in agreement with the LMTO calculation result. The O/Al ratio of A1Ox layer is about 1.9-2.0, which means existence of the higher order oxides than Al2O3. XPS depth profiles showed that the unoxidized Al remains not only near the interface with Co but also near the surface when the deposited Al layer thickness is thick.

AB - Oxidation states of AlOx in Co/AlOx/Co spin tunneling junctions were studied using X-ray photoelectron spectroscopy. Co(10nm)/AlOx/Co(50nm) spin tunneling junctions were fabricated on glass substrates by ion-beam mask sputtering. The Al layers were deposited in various thicknesses and were oxidized in pure O2 gas for 24-48 hours at room temperature. Co/AlOx bilayers simultaneously fabricated were analyzed by XPS. The thicker the Al layer is deposited, the more the unoxidized Al remains. MR ratio of the junctions increased as the unoxidized Al decreased, and this result is qualitatively in agreement with the LMTO calculation result. The O/Al ratio of A1Ox layer is about 1.9-2.0, which means existence of the higher order oxides than Al2O3. XPS depth profiles showed that the unoxidized Al remains not only near the interface with Co but also near the surface when the deposited Al layer thickness is thick.

UR - http://www.scopus.com/inward/record.url?scp=12744267807&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=12744267807&partnerID=8YFLogxK

U2 - 10.1557/proc-811-e3.7

DO - 10.1557/proc-811-e3.7

M3 - Conference article

AN - SCOPUS:12744267807

SN - 0272-9172

VL - 811

SP - 431

EP - 436

JO - Materials Research Society Symposium Proceedings

JF - Materials Research Society Symposium Proceedings

T2 - Integration of Advanced Micro- and Nanoelectronic Devices - Critical Issues and Solutions

Y2 - 13 April 2004 through 16 April 2004

ER -

Evaluation of AlO_x in Co/AlO_x/Co spin tunneling junctions by XPS

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this