TUNNEL TYPE MAGNETIC SENSOR HAVING FIXED MAGNETIC LAYER OF COMPOSITE STRUCTURE CONTAINING CoFeB FILM, AND METHOD FOR MANUFACTURING THE SAME

摘要

A second fixed magnetic layer is formed of a CoFeB layer of CoFeB and an interface layer of CoFe or Co provided in that order from the bottom. An insulating barrier layer composed of Al-O is formed on the second fixed magnetic layer. When a lamination structure composed of CoFeB/CoFe/Al-O is formed as described above, a low RA and a high rate of change in resistance (DeltaR/R) can be simultaneously obtained. In addition, variations in RA and rate of change in resistance (DeltaR/R) can be suppressed as compared to that in the past.