| 摘要 |
PROBLEM TO BE SOLVED: To form an insulating layer in a short time and obtain an MR ratio with a higher performance stability by forming an aluminum layer as an insulator layer through vapor deposition and oxidizing the layer by plasma in an ambience including oxygen. SOLUTION: In a method for forming an insulator layer, a film of metallic aluminum is formed by vapor deposition and is plasma oxidized. A first ferromagnetic layer as a face of the insulator layer where the film is to be formed is more preferably formed by sputtering than the vapor deposition. When the vapor deposited aluminum is oxidized to be the insulating layer, plasma oxidation is used for the oxidation, so that the aluminum can be oxidized to an equal level in a short time as compared with natural oxidation, and the insulating film can be obtained with a resistance value approximately in an equal level in a short time. Particularly when the plasma oxidation is applied to the vapor deposited aluminum layer to obtain the insulating film, a tunneling element of a superior stability and a larger MR ratio can be obtained.
|
