Browse Prior Art Database

TUNNEL VALVE/CPP GMR COMPOSITE STRUCTURE

IP.com Disclosure Number: IPCOM000015318D
Original Publication Date: 2001-Dec-25
Included in the Prior Art Database: 2003-Jun-20
Document File: 1 page(s) / 36K

Publishing Venue

IBM

Abstract

We disclose a magnetic sensor structure where CPP MTJ (Magnetic tunnel junction sensor) and CPP GMR are connected in series with a common Free layer. The combined sensor improves dR/R, V50, and reduces the ferromagnetic coupling at the Free layer. The structure is follows:

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

TUNNEL VALVE/CPP GMR COMPOSITE STRUCTURE

    We disclose a magnetic sensor structure where CPP MTJ (Magnetic tunnel junction sensor) and CPP GMR are connected in series with a common Free layer. The combined sensor improves dR/R, V50, and reduces the ferromagnetic coupling at the Free layer. The structure is follows:

seed/CoFe/Ru/CoFe/AlOx/CoFe/CuOx/CoFe/Ru/CoFe/Cap

The CoFe layer between the AlOx and CuOx spacers is the Free layer. The positive coupling field from the AlOx side and negative coupling field from the CuOx side balance at the Free layer providing Free layer with very low ferromagnetic coupling between the pinned and Free layers. In-addition, dR/R increases due to addition of dR/R from MTJ and GMR. It is to be noted that pinned layers are antiparallel pinned for both MTJ and GMR sensors. No antiferromagnetic pinning applied to the outer CoFe layers.

1