Tunnel type magnetic sensor having fixed magnetic layer of composite structure containing CoFeB film and method for manufacturing the same

摘要

A fixed magnetic layer (4) has a laminated structure composed of a first fixed magnetic layer (4a), an interface layer (4b) of CoFe or Co, and a second fixed magnetic layer (4c) formed of CoFeB provided in that order from the bottom. An insulating barrier layer (5) 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 (”R/R) can be simultaneously obtained. In addition, variations in RA and rate of change in resistance (”R/R) can be suppressed as compared to that in the past.