Title :
Perpendicular current giant magnetoresistance in 0.4 μm diameter Co-Cu multilayer sensors
Author :
Spallas, J.P. ; Huai, Y. ; Vernon, S. ; Fuchs, B. ; Law, B. ; Kania, D.R. ; Kroes, D. ; Thomas, M. ; Kane, D.O. ; Tan, Z.C.H.
Author_Institution :
Lawrence Livermore Nat. Lab., CA, USA
fDate :
9/1/1996 12:00:00 AM
Abstract :
We have fabricated a novel giant magnetoresistive (GMR) multilayer (ML) flux sensor that is designed to operate in the current perpendicular to the plane (CPP) mode. The CPP-GMR sensor is a 0.4 μm diameter, 0.09 μm tall Co-Cu ML pedestal. The sensors are patterned using electron beam lithography. The Al2O3-TiC substrate is coated with a sputter deposited Al2O3 film that is polished to <0.2 nm root mean square (RMS) roughness. Contact to the bottom of the CPP-GMR sensor is made by depositing and Co-Cu multilayers onto a smooth 0.45 μm thick Mo-Si ML stack. The top contact is self-aligned to the CPP-GMR sensor. This is accomplished, in part, by chemical mechanical polishing (CMP). The top and bottom contacts are electrically isolated by a plasma enhanced chemical vapor deposited (PECVD) Si3N4 film. The configuration of the contacts allows four point probe resistance measurements. The CPP-GMR coefficient for these 0.4 μm diameter sensors is 13%
Keywords :
cobalt; copper; electron beam lithography; ferromagnetic materials; giant magnetoresistance; magnetic multilayers; magnetic sensors; magnetoresistive devices; plasma CVD coatings; polishing; surface topography; 0.09 mum; 0.4 mum; Al2O3; Al2O3-TiC; Al2O3-TiC substrate; CPP mode; CPP-GMR coefficient; CPP-GMR sensor; Co-Cu; Co-Cu ML pedestal; Co-Cu multilayer sensors; GMR multilayer flux sensor; PECVD Si3N4 film; RMS roughness; Si3N4; TiC; chemical mechanical polishing; electron beam lithography; four point probe resistance measurements; giant magnetoresistive multilayer; perpendicular current giant magnetoresistance; plasma enhanced chemical vapor deposited film; root mean square roughness; sputter deposited Al2O3 film; top contact; Chemical sensors; Contacts; Electron beams; Giant magnetoresistance; Lithography; Magnetic multilayers; Magnetic sensors; Mechanical sensors; Root mean square; Substrates;
Journal_Title :
Magnetics, IEEE Transactions on
