METHOD OF FORMING TUNNEL BARRIER LAYER, AND TMR SENSOR AND METHOD OF MANUFACTURING THE SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a method of forming a tunnel barrier layer having improved uniformity of thickness and oxidizing condition, and a tunneling magnetoresistive (TMR) sensor having such a tunnel barrier layer, and to provide a method of manufacturing the sensor.;SOLUTION: A tunnel barrier layer 28 of a TMR sensor is in a three-layer stacked structure of a lower Mg layer 25, an MgO layer 26, and an upper Mg layer 27. The MgO layer 26 is formed by naturally oxidizing a surface of the lower Mg layer 25. Thus, uniformity of thickness and oxidizing condition is improved. Moreover, the upper Mg layer 27 is added, thereby oxidation of an adjacent free layer 29 is prevented. Consequently, even if a sensor has a low RA value, a high MR ratio is obtained in the sensor compared with a usual TMR sensor having a tunnel barrier layer including AlO_x.;COPYRIGHT: (C)2007,JPO&INPIT