Title :
Angular sensor using tunneling magnetoresistive junctions with an artificial antiferromagnet reference electrode and improved thermal stability
Author :
Rührig, Manfred ; Seidel, Robert ; Bär, Ludwig ; Rupp, Günter ; Vieth, Michael ; Wecker, Joachim
Author_Institution :
Siemens Corporate Res., Erlangen, Germany
Abstract :
Magnetic tunneling junctions (MTJs) are fabricated using CoFe-Ru-CoFe artificial antiferromagnet (AAF) sandwiches as a hard-magnetic reference layer and plasma-oxidized aluminum as a tunnel barrier. Tailoring the magnetic properties of the artificial antiferromagnet reference layer allows an on-chip magnetization (initialization) of individual junctions, which makes it possible to build monolithic bridges in a Wheatstone arrangement without multiple mask process steps or on-chip heating elements. The functionality of an angular field sensor based on this concept is demonstrated in detail. The thermal stability of such a sensor is investigated and the limitations of the concept are discussed.
Keywords :
magnetic field measurement; magnetic multilayers; magnetic sensors; magnetic tunnelling; semiconductor junctions; CoFe-Ru-CoFe; Wheatstone arrangement; angular sensor; artificial antiferromagnet reference electrode; artificial antiferromagnet sandwiches; hard-magnetic reference layer; magnetic field measurement; magnetic properties; magnetic tunneling junctions; magnetoresistive devices; monolithic bridges; multiple masking; on-chip heating elements; on-chip magnetization; plasma-oxidized aluminum; thermal stability; tunnel barrier; tunneling magnetoresistive junctions; Aluminum; Antiferromagnetic materials; Electrodes; Magnetic sensors; Magnetic tunneling; Plasma properties; Plasma stability; Thermal sensors; Thermal stability; Tunneling magnetoresistance;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2003.821571
