Angular sensor using TMR junctions with an AAF (artificial antiferromagnet) reference electrode and improved thermal stability

Author

Ruhrig, M. ; Seidel, R. ; Bar, L. ; Rupp, G. ; Vieth, Moritz ; Wecker, J.

Author_Institution

Siemens AG, Erlangen, Germany

fYear

2002

Abstract

Summary form only given. Magnetic tunnel junctions (MTJs) were fabricated using CoFe/Ru/Co/Fe artificial antiferromagnet (AAF) sandwiches as a hard-magnetic reference layer and plasma oxidized aluminum as a tunnel-barrier. Tailoring the magnetic properties of the AAF reference layer allows an on-chip magnetization (initialization) of individual junctions which makes it possible to built monolithic bridges in Wheatstone arrangement without multiple mask process steps or on-chip heating elements. The functionality of an angular field sensor based on this concept are demonstrated in detail together with the thermal stability test results and the limitations are discussed.

Keywords

antiferromagnetism; bridge circuits; integrated circuit design; integrated circuit measurement; magnetic field measurement; magnetic sensors; magnetisation; thermal stability; tunnelling magnetoresistance; AAF layer magnetic properties; AAF sandwiches; Al/sub 2/O/sub 3/; CoFe-Ru-Co-Fe; CoFe/Ru/Co/Fe artificial antiferromagnet sandwiches; MTJ; TMR junctions; angular magnetic field sensors; artificial antiferromagnet reference electrode; hard-magnetic reference layers; individual junction on-chip magnetization; magnetic tunnel junctions; monolithic Wheatstone bridges; multiple mask process steps; on-chip heating elements; on-chip initialization; plasma oxidized aluminum tunnel-barrier; thermal stability improvement; Aluminum; Antiferromagnetic materials; Electrodes; Iron; Magnetic sensors; Magnetic tunneling; Plasma properties; Plasma stability; Thermal sensors; Thermal stability;

fLanguage

English

Publisher

ieee

Conference_Titel

Magnetics Conference, 2002. INTERMAG Europe 2002. Digest of Technical Papers. 2002 IEEE International

Conference_Location

Amsterdam, The Netherlands

Print_ISBN

0-7803-7365-0

Type

conf

DOI

10.1109/INTMAG.2002.1000766

Filename

1000766