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

Volume

32

Issue

5

fYear

1996

fDate

9/1/1996 12:00:00 AM

Firstpage

4710

Lastpage

4712

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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.539126

Filename

539126