| 摘要 |
PROBLEM TO BE SOLVED: To improve heat resistance and an MR ratio by forming a tunnel insulation film due to the oxidation of a non-magnetic metal layer and setting the thickness of the non-magnetic metal layer to a specific value or less. SOLUTION: In a ferromagnetic tunnel junction 20, an NiFe layer 21A1 with a thickness of, for example, 17.1 nm, for constituting a lower ferromagnetic layer 21A, a Co layer 21A2 with a thickness of, for example, 3.3 nm, an insulation barrier layer 21C, a Co layer 21B1 with a thickness of, for example, 3.3 nm, for constituting an upper ferromagnetic layer 21B, an NiFe layer 21B2 with a thickness of, for example, 17.1 nm, an FeMn layer 22 with antiferromagnetism, and an NiFe layer 23 a thickness of, for example, 8.6 nm, are successively formed on an Si substrate 20A that is covered with an SiO2 film 20B. In this case, the insulation barrier layer 21C is formed by Al film being formed on the ferromagnetic layer 21A, and its thickness is set to approximately 0.5 nm or more and approximately 1.7 nm or less, thus obtaining a magnetic resistance change rate that is extremely close to a theoretical value between lower and upper ferromagnetic layers. |
