Monolithically integrated GMR angle sensors for automotive applications with extended magnetic stability

Konferenz: Sensoren und Messsysteme 2014 - Beiträge der 17. ITG/GMA-Fachtagung
03.06.2014 - 04.06.2014 in Nürnberg, Deutschland

Tagungsband: Sensoren und Messsysteme 2014

Seiten: 4Sprache: EnglischTyp: PDF

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Bever, Thomas; Raberg, Wolfgang; Zimmer, Juergen (Infineon Technologies AG, Am Campeon 1-12, 85579 Neubiberg, Germany)
Pruegl, Klemens; Strasser, Andreas (Infineon Technologies AG, Wernerwerkstr. 2, 93049 Regensburg, Germany)

A monolithically integrated GMR angle sensor for automotive applications is presented. The vertical integration concept allows a combination of our spin-valve type GMR angle sensors with conventional CMOS or bipolar base technologies providing the signal conditioning. The PtMn based sensor stack exhibits an excellent thermal stability. A combination of temperature and magnetic field, however, leads to a drift of the magnetization direction of the reference system and therefore, to an increased angular error. A reduction of the net magnetic moment as well as the film thickness of the pinned and reference layer of the artificial antiferromagnet leads to a significant improvement of the robustness against thermo-magnetic stress. As a result, an overall angular error of <1deg over lifetime at magnetic inductions up to 90mT and 150deg C is obtained.