MAGNETORESISTANCE SENSOR, ITS PRODUCTION, OPTIMIZING METHOD FOR INTERFACE CHARACTERISTICS AND OPTIMIZING METHOD FOR MAGNETORESISTANCE RESPONSE

摘要

PROBLEM TO BE SOLVED: To increase the magnetoresistance output by inserting a conductive spacer between a ferromagnetic material layer and a ferromagnetic material layer to constitute a spin valve sensor and a GMR sensor and controlling the difference of electronegativity between the ferromagnetic layers and the spacer to the min. SOLUTION: The spin valve sensor 10 consists of two ferromagnetic(FM) layers (FM1 and FM2) separated by a conductive spacer, namely a layer 12. The sensor 10 is formed on a nonmagnetic substrate, on which a buffer layer having about 25 to 100Å thickness is formed. The buffer layer consists of Ta, Cr, Fe, Pt, Pd, Ir or Au. The FM layers FM1 and FM2 may have a same compsn. or different compsn. Mismatching in the electronegativity causes the absolute difference of electronegativity between the FM layer and the conductive spacer, namely, the potential barrier on the interface relating to |x|.